Cryptography Tutorial

Cryptography Tutorial

The management of corporations, organizations, military activities, etc., depends heavily on information. Information in the wrong hands can have disastrous effects or cause corporate losses. A company can employ cryptology to encrypt information and safeguard communication. Cryptology entails converting data from a format that is human-readable to an unreadable one and vice versa.

Questions about the privacy and safety of personal information are common in today’s digital world. Due to the widespread use of encryption and cryptography, some of these issues have been resolved. You will discover more about cryptography and its numerous facets here. This tutorial on “What is Cryptography” covers the following subjects:

Table of Contents

What is Cryptography

Cryptography is the study of techniques for securing communication and data in the presence of adversaries. It hides the real meaning of the data by transforming it into a non-readable format by humans. It deals with analyzing and developing protocols that prevent the entry of malicious third parties from accessing data from being shared between the entities. In cryptography, an adversary is a malevolent entity that aims to retrieve data by mining the principles of information security.

The four principles of modern-day cryptography are as follows:

  • Data Confidentiality: Data Confidentiality refers to the guidelines and rules to follow to ensure the data is restricted to certain places or people.
  • Data Integrity: Data Integrity refers to maintaining and ensuring data accuracy and consistency over its life cycle.
  • Authentication: Authentication is the process of ensuring the data being claimed by the user belongs to it.
  • Non-repudiation: It refers to the capability to make sure a person associated with the contract cannot deny the authentication of the signature over the documents.

The evolution of Cryptography

Cryptography is the backbone of our current digital society, but how did it become so important? Interestingly, the systematic study of cryptography as a science (and perhaps as an art) started only during the past 100 years.

Greek words Krypto and graphein, which translate to “hide” and “writing,” are the origin of the word cryptography. Simple writing was the original kind of cryptography since most people could not read it (New World, 2007). Later, the majority of the great civilizations sent crucial confidential information using some sort of encryption. A cipher was the first type of cryptography (a cipher is an algorithm used for encryption or decryption). Ciphers had the drawback of being easily cracked using the letter frequency, and once a universal method of doing so was discovered, they were rendered useless.

Middle ages to today

The first cryptographic key was discovered in the 1600s, and this marked the beginning of the next major development by shifting the focus from system security to key security. Even if the system was open to the public, a key was required to read the message. That avoided the issue where a system’s mechanism rendered the system as a whole outmoded.

Then, during the 19th Century the first use of a rotor for encryption was recorded. In the 20th Century, the invention of the Enigma machine (used by the German military during WWII) was a technical milestone, being one of the hardest ciphers to break. However, that too was eventually broken by Poland, and British cryptographers designed a means to obtain the daily key.

Following the war, cryptography began to be used in business, with IBM being the first organization to methodically create a crypto-group and what would eventually become the first American standard for encryption. The standard, however, was short-lived because a brute-force attack, a straightforward but extremely effective technique, also managed to defeat it. Simply testing every combination is what brute force involves, and it is a tremendously computationally costly procedure. The complexity of the private keys also rises in response to increases in processing capacity for the same reason.

Cryptography has been a continuous game of chase between the complexity of the cryptographic keys and the computing power available. In principle, any key is vulnerable to a brute-force attack; the more complex the key, the more time-consuming such an attack is.

The importance of Cryptographyin the digital age

Advances in technology and computing power have enabled people to move more and more of their data to the digital sphere. Moving data through any digital means—aside from the obvious advantage it brings to speed, accessibility, and convenience—comes with the mirroring disadvantage of being harder to protect.

The need to protect digital data from being used for unlawful purposes is being tackled by cryptography. However, as with all rights, there are competing interests. Law enforcement has a legitimate right to intercept communications in certain circumstances. Balancing these rights requires a balance known as the tightrope between security and privacy.

The importance of cryptography can be summarized by the fact that it is the only tool the user has in the digital world to protect their private data. And as we move more and more into the digital world, association, and cryptography is becoming more and more important.

The state of Cryptographytoday

These days, “public-key cryptography” or “asymmetric cryptography” have become more common due to the requirement to connect with parties we may not always be able to trust. Public keys used by the sender to encrypt the message and private keys held by the recipient used for message decryption are the foundation of this type of encryption. Because of the one-way nature of this process, only the sender can understand the message. These cutting-edge techniques are nonetheless susceptible to failure. If nothing else, a brute-force attack that iterates through all potential keys can defeat an algorithm. Modern cryptography, therefore, aims to develop techniques that make it computationally impossible for an attacker to recover the private key.

What about privacy?

Modern cryptographic protocols are nearly impossible to crack due to the necessary computation time, but businesses and individuals are constantly looking for new ways to conduct business more privately. Recently, individuals and organizations concerned with privacy have turned their attention to trust as a result of improvements in processing power and cryptography. Cryptographers have thought that if it is possible to encrypt and effectively hide the data from people who don’t have to see it, perhaps there is a way to still transact with them without showing the data. And sure enough, during the 1980s, tools such as zero-knowledge proofs and calculations on encrypted data were discovered. By applying mathematical transformations to the underlying data, these tools enable people to interact with and validate encrypted data, effectively creating another revolution in the field. Now the data exchange can be private, even between parties that transact directly.

Increased efficiency for high-demand protocols

In 2012 Project Pinocchio from IBM and Microsoft found a way to reduce the computing needs of a zero-knowledge proof by 20x and for zero-knowledge verification by more than 50x, making it efficient enough for practical uses. It now can be used to hide the data between two parties and still allow them to transact, not only theoretically, but fast enough to have private and commercial applications. This breakthrough opened new possibilities to businesses and researchers, who started wondering what other applications are within reach and what other technological possibilities exist.

That same curiosity is what drove us at codelivly to explore these technologies in the first place. Our team develops novel implementations for cutting-edge and privacy-preserving technologies. We explore applications such as: 

  • Secure and private online voting
  • Augmented privacy for exchanges, enabling them to not have to reveal their whole order book    
  • A bulletproof way for anyone to provide proof of cryptographic assets without ever revealing the funds available in one’s account
  • A marketplace for alternative data providers and buyers that enables businesses to try the data before deciding to buy it, while keeping the data hidden.
  • Making possible a demonstration of the predictive power of a model on new data without disclosing the model or the data

Recent and ongoing research by codelivly and other open-source initiatives, as well as the demand for greater security and privacy in personal and commercial datasets, have made all these applications possible.

What does the future of cryptography hold?

Quantum computing

These innovative breakthroughs and discoveries in cryptography are fostering a promising future for the discipline. The biggest shift that’s supposedly coming is quantum computing. The computer capacity at our disposal can be exponentially increased via quantum computing, which uses the characteristics of superpositioned particles. This implies that the cryptographic operations that are currently too complex to operate on silicon chips could be made feasible on a quantum device, potentially rendering current encryption obsolete.

Homomorphic encryption

Today, we encrypt data as it travels over the internet and when it is at rest on a storage device. But we have to decrypt data to use it or analyze it, creating a potential security vulnerability. Homomorphic encryption is a new idea that solves that problem, allowing users to process data without decrypting it. With homomorphic encryption, we process encrypted data and produce encrypted results. And while this is not a novel idea, new breakthroughs that vastly improved performance bring the possibility of efficient encrypted data processing back to the forefront.

Cryptography Algorithm

Cryptography is a branch of science that focuses on reversibly altering data to provide data security. A cryptographic algorithm is a method for changing data from a readable format (plaintext) to a secure format (ciphertext) and back again. The process of converting plaintext to ciphertext is known as encryption. The process of decryption converts ciphertext to plaintext.

Cryptography is broadly classified into two categories: Symmetric key Cryptography and Asymmetric key Cryptography (popularly known as public key cryptography).

encryption algorithms-what is cryptography-edureka

Now Symmetric key Cryptography is further categorized as Classical Cryptography and Modern Cryptography.

Further drilling down, Classical Cryptography is divided into Transposition Cipher and Substitution Cipher. On the other hand, Modern Cryptography is divided into Stream Cipher and Block Cipher.

So, let’s understand these algorithms with examples.

How do various cryptographic algorithms work?

Let’s start with the Symmetric key encryption

Symmetric Key Cryptography

a type of encryption where the sender and recipient of communication use the same key to encrypt and decode the message. The Data Encryption Standard (DES) is the most widely used symmetric-key system (DES)

symmetric key-what is cryptography-edureka

Transposition Ciphers

In Cryptography, a transposition cipher is a method of encryption by which the positions held by units of plaintext (which are commonly characters or groups of characters) are shifted according to a regular system so that the ciphertext constitutes a permutation of the plaintext. 

That is, the order of the units is changed (the plaintext is reordered). Mathematically, a bijective function is used on the characters’ positions to encrypt and an inverse function to decrypt.


transposition cipher-what is cryptography-edureka

Substitution Cipher

Example: The term “units” can refer to single letters (the most common), pairs of letters, triplets of letters, blends of the above, and other combinations of letters. This method of encryption replaces units of plaintext with ciphertext, according to a fixed system.

Consider this example shown on the slide: Using the system just discussed, the keyword “zebras” gives us the following alphabets:

substitution cipher example-what is cryptography-edureka

Stream Cipher

Stream cipher-what is cryptography-edureka

Symmetric or secret-key encryption algorithm that encrypts a single bit at a time. With a Stream Cipher, the same plaintext bit or byte will encrypt to a different bit or byte every time it is encrypted.

Block Cipher

An encryption method that applies a deterministic algorithm along with a symmetric key to encrypt a block of text, rather than encrypting one bit at a time as in stream ciphers 

Block cipher-aht is cryptography-edureka

Example: AES, a popular block cipher, encrypts 128-bit blocks using a key that is 128, 192, or 256 bits long. Block ciphers are a class of pseudorandom permutation (PRP) families that work with blocks of fixed size. PRPs are deemed dependable until they are shown to be unreliable since they are functions that cannot be distinguished from truly random permutations.

Asymmetric Key Encryption (or Public Key Cryptography)

public-key encryption-what is cryptography-edureka

The encryption process where different keys are used for encrypting and decrypting the information. Keys are different but are mathematically related, such that retrieving the plain text by decrypting ciphertext is feasible. 

RSA is the most widely used form of public key encryption, 

RSA Algorithm

  • RSA stands for Rivest, Shamir, and Adelman, inventors of this technique
  • Both public and private key are interchangeable
  • Variable Key Size (512, 1024, or 2048 bits)
RSA encryption-what is cryptography-edureka

Here’s how keys are generated in RSA algorithm

What Is the Need for Cryptography?

Cryptography remains important to protecting data and users, ensuring confidentiality, and preventing cyber criminals from intercepting sensitive corporate information. Common uses and examples of cryptography include the following:

Common Uses of Cryptography

Privacy and Confidentiality

Every day, people and organizations use cryptography to safeguard their privacy and maintain the secrecy of their communications and data. By encrypting communicated messages with an algorithm and a key that is only known to the sender and receiver, cryptography maintains confidentiality. The messaging app WhatsApp is a typical illustration of this, as it encrypts chats between users to prevent h4king or interception.

Cryptography also secures browsing, such as with virtual private networks (VPNs), which use encrypted tunnels, asymmetric encryption, and public and private shared keys.



Cryptography can demonstrate the integrity of the information delivered and received in a manner similar to how it can verify the veracity of a message. Information cannot be changed while being stored or while being transported between a sender and a recipient, thanks to cryptography. Digital signatures, for instance, can spot fraud or manipulation in the delivery of software and financial transactions.


Cryptography confirms accountability and responsibility from the sender of a message, which means they cannot later deny their intentions when they created or transmitted information. Digital signatures are a good example of this, as they ensure a sender cannot claim a message, contract, or document they created to be fraudulent. Furthermore, in email nonrepudiation, email tracking makes sure the sender cannot deny sending a message and a recipient cannot deny receiving it.

Key Exchange

Key exchange is the method used to share cryptographic keys between a sender and their recipient. 

What is Cryptanalysis?

Cryptanalysis is the study of ciphertext, ciphers, and cryptosystems with the goal of understanding their operation and developing methods for circumventing or weakening them. Cryptanalysts, for instance, target safe hashing, digital signatures, and other cryptographic methods in their pursuit to decrypt ciphertexts without having access to the plaintext source, encryption key, or methodology that was used to encrypt it.

How does cryptanalysis work?

While the goal of cryptanalysis is to identify flaws in cryptographic algorithms or otherwise undermine them, cryptographers employ the research findings of cryptanalysts to enhance or replace weak methods. Cryptology, the mathematical study of codes, ciphers, and related algorithms, includes both cryptanalysis, which focuses on deciphering encrypted data, and cryptography, which focuses on developing and enhancing encryption ciphers and other methods.

Researchers may discover methods of attack that completely break an encryption algorithm, which means that ciphertext encrypted with that algorithm can be decrypted trivially without access to the encryption key. More often, cryptanalytic results uncover weaknesses in the design or implementation of the algorithm, which can reduce the number of keys that need to be tried on the target ciphertext.

For example, a cipher with a 128-bit encryption key can have 2128 (or 340,282,366,920,938,463,463,374,607,431,768,211,456) unique keys; on average, a brute force attack against that cipher will succeed only after trying half of those unique keys. If cryptanalysis of the cipher reveals an attack that can reduce the number of trials needed to 240 (or just 1,099,511,627,776) different keys, then the algorithm has been weakened significantly, to the point that a brute-force attack would be practical with commercial off-the-shelf systems.

Who uses cryptanalysis?

Cryptanalysis is practiced by a broad range of organizations, including governments aiming to decipher other nations’ confidential communications; companies developing security products that employ cryptanalysts to test their security features; and h4kers, crackers, independent researchers, and academicians who search for weaknesses in cryptographic protocols and algorithms.

It is this constant battle between cryptographers trying to secure information and cryptanalysts trying to break cryptosystems that moves the entire body of cryptology knowledge forward.

Cryptanalysis techniques and attacks

Depending on how much knowledge the analyst has about the ciphertext being examined, there are numerous distinct cryptanalysis attacks and methodologies. Cryptanalysis techniques include:

  • The attacker only has access to one or more encrypted messages in a ciphertext-only attack and is unaware of the plaintext data, the encryption algorithm being used, or any information on the cryptographic key being utilized. When intelligence services have decrypted an adversary’s encrypted communications, they frequently confront challenges like this. In a known plaintext attack, the analyst may have access to some or all of the plaintext of the ciphertext; the analyst’s goal, in this case, is to discover the key used to encrypt the message and decrypt the message. Once the key is discovered, an attacker can decrypt all messages that have been encrypted using that key.
  • Linear cryptanalysis is a type of known plaintext attack that uses a linear approximation to describe how a block cipher works. Known plaintext attacks depend on the attacker being able to discover or guess some or all of an encrypted message, or even the format of the original plaintext. For example, if the attacker is aware that a particular message is addressed to or about a particular person, that person’s name may be a suitable known plaintext.
  • In a selected plaintext attack, the analyst either has access to the encryption equipment or is aware of the encryption technique. To learn more about the key, the analyst can encrypt the selected plaintext using the chosen algorithm.
  • A differential cryptanalysis attack is a type of chosen plaintext attack on block ciphers that analyzes pairs of plaintexts rather than single plaintexts, so the analyst can determine how the targeted algorithm works when it encounters different types of data.
  • Integral cryptanalysis attacks are similar to differential cryptanalysis attacks in that they use sets of plaintexts in which part of the plaintext is kept constant but the rest of the plaintext is modified. This attack can be especially useful when applied to block ciphers that are based on substitution-permutation networks.
  • A side-channel attack depends on information collected from the physical system being used to encrypt or decrypt. Successful side-channel attacks use data that is neither the ciphertext resulting from the encryption process nor the plaintext to be encrypted but rather may be related to the amount of time it takes for a system to respond to specific queries, the amount of power consumed by the encrypting system, or electromagnetic radiation emitted by the encrypting system.
  • A dictionary attack is a technique typically used against password files and exploits the human tendency to use passwords based on natural words or easily guessed sequences of letters or numbers. The dictionary attack works by encrypting all the words in a dictionary and then checking whether the resulting hash matches an encrypted password stored in the SAM file format or another password file.
  • Attacks known as “man-in-the-middle” happen when cryptanalysts figure out how to get in the way of two parties trying to exchange keys for secure communication using asymmetric or public key infrastructure. The original parties believe they are exchanging keys with each other when in fact the attacker performs a key exchange with each of them. The attacker’s keys are ultimately used by the two parties.

Other types of cryptanalytic attacks can include techniques for convincing individuals to reveal their passwords or encryption keys, developing Trojan horse programs that steal secret keys from victims’ computers and send them back to the cryptanalyst or tricking a victim into using a weakened cryptosystem.

Side-channel attacks have also been known as timing or differential power analysis. These attacks came to wide notice in the late 1990s when cryptographer Paul Kocher was publishing results of his research into timing attacks and differential power analysis attacks on Diffie-Hellman, RSA, Digital Signature Standard (DSS), and other cryptosystems, especially against implementations on smart cards.

Tools for cryptanalysis

Because cryptanalysis is primarily a mathematical subject, the tools for doing cryptanalysis are in many cases described in academic research papers. However, there are many tools and other resources available for those interested in learning more about doing cryptanalysis. Some of them include:

  • CrypTool is an open-source project that produces e-learning programs and a web portal for learning about cryptanalysis and cryptographic algorithms.
  • Cryptol is a domain-specific language originally designed to be used by the National Security Agency to specify cryptographic algorithms. Cryptol is published under an open source license and is available for public use. Cryptol makes it possible for users to monitor how algorithms operate in software programs written to specify the algorithms or ciphers. Cryptol can be used to deal with cryptographic routines rather than with entire cryptographic suites.
  • CryptoBench is a program that can be used to do cryptanalysis of ciphertext generated with many common algorithms. It can encrypt or decrypt with 29 different symmetric encryption algorithms; encrypt, decrypt, sign and verify with six different public key algorithms; and generate 14 different kinds of cryptographic hashes as well as two different types of checksum.
  • Ganzúa (meaning picklock or skeleton key in Spanish) is an open-source cryptanalysis tool used for classical polyalphabetic and monoalphabetic ciphers. Ganzúa lets users define nearly completely arbitrary cipher and plain alphabets, allowing for the proper cryptanalysis of cryptograms obtained from the non-English text. A Java application, Ganzúa can run on Windows, Mac OS X or Linux.

Cryptanalysts commonly use many other data security tools including network sniffers and password cracking software, though it is not unusual for cryptanalytic researchers to create their own custom tools for specific tasks and challenges.

Requirements and responsibilities for cryptanalysts

It may be the responsibility of a cryptanalyst to create algorithms, cipher, and security systems to encrypt sensitive data and information as well as to examine and decrypt various types of hidden information, such as encrypted data, cipher texts, and telecommunications protocols, in cryptographic security systems.

Government agencies as well as private sector companies hire cryptanalysts to ensure their networks are secure and sensitive data transmitted through their computer networks is encrypted.

Other duties that cryptanalysts may be responsible for include:

  • protecting critical information from being intercepted copied, modified or deleted.
  • evaluating, analyzing, and targeting weaknesses in cryptographic security systems and algorithms.
  • designing security systems to prevent vulnerabilities.
  • Developing mathematical and statistical models to analyze data and solve security problems.
  • testing computational models for accuracy and reliability.
  • investigating, researching, and testing new cryptologic theories and applications.
  • searching for weaknesses in communication lines.
  • Ensuring financial data is encrypted and accessible only to authorized users.
  • Ensuring message transmission data isn’t h4ked or altered in transit.
  • encoding cryptic messages and coding systems for military, law enforcement, and other government agencies.
  • Developing new methods to encrypt data as well as new methods to encode messages to conceal sensitive data.

Individuals planning to pursue a career in cryptanalysis are advised to obtain a bachelor’s degree in computer science, computer engineering, mathematics or a related field; some organizations will consider hiring individuals without a technical degree if they have extensive training and prior work experience in the field.

A Master of Science degree is also strongly recommended, unless the candidate already has a bachelor’s degree in mathematics and computer science. The strongest candidates will have a doctoral degree in mathematics or computer science with a focus on cryptography. 

What Are the Applications of Cryptography?

Cryptography finds use in many areas, ranging from safety in payment portals, to secure messaging platforms like WhatsApp. A few of those applications are as follows –


1. SSL/TLS Encryption:

Browsing the internet is secure today primarily because cryptography has allowed you to encrypt your data flow. Starting from browser identification to server authentication, encryption and cryptography, in general, have simplified online browsing.

2. Digital Signatures:

With digital contracts gaining prominence, the world was in the need of a secure channel to pass critical documents through. Cryptography helps provide a layer of authentication so you can be certain regarding the origin, confidentiality, and integrity of your documents.

3. Safe Online Banking:

Online banking services and payment applications would be an afterthought, if not for encryption of data. Cryptography has enabled authentication systems to verify the identity of certain individuals before allowing them to hold transactions and help reduce credit card fraud in the process.

4. Secure Chatting Services:

A new end-to-end encryption protocol has been implemented by messaging services like WhatsApp, Telegram, and Signal, ensuring that only the sender and recipient can read the messages. This is a significant improvement over the days of SMS, when security was never guaranteed. There are numerous communication platforms available because of cryptography.

5. Encrypted Emails:

With a vast amount of private information passing through your inbox, having a secure method of communication is an absolute necessity. Thanks to encryption algorithms like PGP (Pretty Good Privacy), your emails are now encrypted at all times.

6. Crypto-Currency:

Cryptocurrency has had an exponential rise in interest rates thanks to blockchain technology and is still one of the most sought-after trade markets in existence today. Today’s digital world has a truly decentralized, secure, and tamper-proof system owing to encryption.

With so many different avenues where cryptography has found its place, its implementation is distinct. In the next section on ‘what is cryptography’, you will understand how to go ahead with it.


An open-source program called CrypTool is utilized in many different cryptanalysis and cryptography techniques. It has the ability to examine both encryption and decryption for various algorithms. Better instructions for achieving encryption and decryption, a number of algorithms, a graphical user interface, and packages of analytics tools are all provided by CrypTool.

Download the CrypTool version and let’s try to create the RC4 stream cipher.

Creating the RC4 stream cipher

To create the RC4 stream cipher, do the following steps:

  • Open CrypTool.
  • Click on File in the Menu bar and select New.
  • Enter some text in the window, as shown in the figure.
  • Click on Encrypt/Decrypt option in the menu bar, select Symmetric (modern) from the list, and select RC4 from the list.
  • A window opens, enter the key length and click on Encrypt.
  • You will get the stream cipher encrypted code, as shown in the figure.
  • To decrypt the text, click on Encrypt/Decrypt option in the menu bar, select Symmetric (modern) from the list, and select RC4 from the list.
  • A window opens, enter the key length and click Decrypt.
  • You will see the decrypt stream ciphertext, as shown in the figure.

Attacking the stream cipher

To attack the stream cipher, do the following steps:

  • Click on Analysis on the menu bar, select Symmetric Encryption (modern), and select RC4 from the list.
  • Select the key length and make sure that the secret key length and this key length are of the same bits.
  • Click Start. It takes time to complete the analysis. The time taken depends on the length of key length and the processing capacity of the machine.
  • You will get the results when the analysis is completed.

H4king Activity: How to create a Cipher using CrypTool

In this practical CryptoOL tutorial, we will create a simple cipher using the RC4 brute force tool. We will then attempt to decrypt it using a brute-force attack. For this exercise, let us assume that we know the encryption secret key is 24 bits. We will use this information to break the cipher.

Creating the RC4 stream cipher

Step 1) Download and install CryptTool

We will use CrypTool 1 as our cryptology tool. CrypTool 1 is an open-source educational tool for cryptological studies. You can download it from

Step 2) Open CryptTool and replace the text

We will encrypt the following phrase

Never underestimate the determination of a kid who is time-rich and cash-poor

We will use 00 00 00 as the encryption key.

  • Open CrypTool 1
How to make your data safe using Cryptography
  • Replace the text with Never underestimate the determination of a kid who is time-rich and cash-poor
How to make your data safe using Cryptography

Step 3) Encrypt the text

  • Click on Encrypt/Decrypt menu
How to make your data safe using Cryptography
  • Point to Symmetric (modern) then select RC4 as shown above
  • The following window will appear
How to make your data safe using Cryptography

Step 4) Select encryption key

  • Select 24 bits as the encryption key
  • Set the value to 00 00 00
  • Click on Encrypt button
  • You will get the following stream cipher
How to make your data safe using Cryptography

Attacking the stream cipher

Step 5) Start Analysis

  • Click on Analysis menu
How to make your data safe using Cryptography
  • Point to Symmetric Encryption (modern) then select RC4 as shown above
  • You will get the following window
How to make your data safe using Cryptography
  • Remember the assumption made is the secret key is 24 bits. So make sure you select 24 bits as the key length.
  • Click on the Start button. You will get the following window
How to make your data safe using Cryptography
  • Note: the time taken to complete the Brute-Force Analysis attack depends on the processing capacity of the machine been used and the key length. The longer the key length, the longer it takes to complete the attack.

Step 6) Analyse the results

  • When the analysis is complete, you will get the following results.
How to make your data safe using Cryptography
  • Note: a lower Entropy number means it is the most likely correct result. It is possible a higher than the lowest found Entropy value could be the correct result.
  • Select the line that makes the most sense then click on Accept selection button when done 

The Ultimate Guide to Symmetric Encryption

A type of encryption known as symmetric encryption uses a single secret key to both encrypt and decrypt digital data. To be used in the decryption procedure, the key must be exchanged between the parties communicating via symmetric encryption. This encryption technique is distinct from asymmetric encryption, which encrypts and decrypts data using a pair of keys—one public and one private.

By using symmetric encryption algorithms, data is “scrambled” so that it can’t be understood by anyone who does not possess the secret key to decrypt it. Once the intended recipient who possesses the key has the message, the algorithm reverses its action so that the message is returned to its original readable form. The secret key that the sender and recipient both use could be a specific password or code, or it could be a random string of letters or numbers that has been generated by a secure random number generator (RNG). For banking-grade encryption, the symmetric keys must be created using an RNG that is certified according to industry standards, such as FIPS 140-2.

What Are the Types of Ciphers Being Used?

Two types of ciphers can be used in symmetric algorithms. These two types are:

  • Stream Ciphers
  • Block Ciphers

1. Stream Ciphers

Stream ciphers are the algorithms that encrypt basic information, one byte/bit at a time. You use a bitstream generation algorithm to create a binary key and encrypt the plaintext.

The process for encryption and decryption using stream ciphers are as follows :

  • Get the plaintext to be encrypted.
  • Create a binary key using the bitstream generation algorithm.
  • Perform XOR operation on the plaintext using the generated binary key.
  • The output becomes the ciphertext.
  • Perform XOR operations on the ciphertext using the same key to get back the plaintext.

The most well-known stream ciphers are RC-4, SALSA and PANAMA.

2. Block Ciphers

On the other hand, block ciphers dissect the raw information into chunks of data of a fixed size. The size depends on the exact cipher being used. A 128-bit block cipher will break the plaintext into blocks of 128-bit each and encrypt those blocks instead of a single digit. These ciphers are slower but much more tamper-proof and are used in some of the most common algorithms being employed today.


Today, the most popular symmetric-key algorithms like AES, DES, and 3DES are block cipher methodology subsets. 

Some examples of symmetric encryption algorithms include:

  • AES (Advanced Encryption Standard)
  • DES (Data Encryption Standard)
  • IDEA (International Data Encryption Algorithm)
  • Blowfish (Drop-in replacement for DES or IDEA)
  • RC4 (Rivest Cipher 4)
  • RC5 (Rivest Cipher 5)
  • RC6 (Rivest Cipher 6)

AES, DES, IDEA, Blowfish, RC5 and RC6 are block ciphers. RC4 is a stream cipher.


In “modern” computing, DES was the first standardized cipher for securing electronic communications and is used in variations (e.g. 2-key or 3-key 3DES). The original DES is not used anymore as it is considered too “weak”, due to the processing power of modern computers. Even 3DES is not recommended by NIST and PCI DSS 3.2, as well as all 64-bit ciphers. However, 3DES is still widely used in EMV chip cards because of legacy applications that do not have a crypto-agile infrastructure.


The most commonly used symmetric algorithm is the Advanced Encryption Standard (AES), which was originally known as Rijndael. This is the standard set by the U.S. National Institute of Standards and Technology in 2001 for the encryption of electronic data announced in U.S. FIPS PUB 197. This standard supersedes DES, which had been in use since 1977. Under NIST, the AES cipher has a block size of 128 bits, but can have three different key lengths as shown with AES-128, AES-192 and AES-256.

What is Symmetric Encryption Used For?

While symmetric encryption is an older method of encryption, it is faster and more efficient than asymmetric encryption, which takes a toll on networks due to performance issues with data size and heavy CPU use. Due to the better performance and faster speed of symmetric encryption (compared to asymmetric), symmetric cryptography is typically used for bulk encryption / encrypting large amounts of data, e.g. for database encryption. In the case of a database, the secret key might only be available to the database itself to encrypt or decrypt. Industry standard symmetric encryption is also less vulnerable to advances in quantum computing compared to the the current standards for asymmetric algorithms (at the time of writing).

Some examples of where symmetric cryptography is used are:

  • Payment applications, such as card transactions where PII needs to be protected to prevent identity theft or fraudulent charges
  • Validations to confirm that the sender of a message is who he claims to be
  • Random number generation or hashing

Key management for symmetric encryption – what we need to consider

Unfortunately, symmetric encryption does come with its own drawbacks. Its weakest point is its aspects of key management, including:

Key Exhaustion

Symmetric Encryption suffers from behavior where every use of a key ‘leaks’ some information that can potentially be used by an attacker to reconstruct the key. The defenses against this behavior include using a key hierarchy to ensure that master or key-encryption keys are not over-used and the appropriate rotation of keys that do encrypt volumes of data. To be tractable, both these solutions require competent key-management strategies as if (for example) a retired encryption key cannot be recovered the data is potentially lost.

Attribution data

Unlike asymmetric (public-key) Certificates, symmetric keys do not have embedded metadata to record information such as expiry date or an Access Control List to indicate the use the key may be put to – to Encrypt but not Decrypt for example.

The latter issue is somewhat addressed by standards such as ANSI X9-31 where a key can be bound to information prescribing its usage. But for full control over what a key can be used for and when it can be used, a key-management system is required.

Key Management at large scale

Where only a few keys are involved in a scheme (tens to low hundreds), the management overhead is modest and can be handled through manual, human activity. However, with a large estate, tracking the expiration and arranging rotation of keys quickly becomes impractical.

Consider an EMV payment card deployment: millions of cards multiplied by several keys-per-card requires a dedicated provision and key-management system. 

The Ultimate Guide to Asymmetric Encryption 

Asymmetric encryption algorithms use two different keys for encryption and decryption. The key used for encryption is the public key, and the key used for decryption is the private key. Both the keys must belong to the receiver.


As you can see in the above image, using different keys for encryption and decryption has helped avoid the problem of key exchange, as seen in the case of symmetric encryption.

For example, if Alice needs to send a message to Bob, both the keys, private and public, must belong to Bob.


The process for the above image is as follows:

  • Step 1: Alice uses Bob’s public key to encrypt the message
  • Step 2: The encrypted message is sent to Bob
  • Step 3: Bob uses his private key to decrypt the message

To understand the asymmetric key cryptography architecture clearly, consider the process of sending and receiving letters via physical mailboxes. 

As shown below, anyone who has the postal address of the receiver (public key in our case) can send any message they want.


However, only the receiver can read all his/her messages thanks to the mailbox key that no other person can have.


This eliminates the need to exchange any secret key between sender and receiver, thereby reducing the window of exploitation.

Now that you understand the base terminology and process behind asymmetric key cryptography, this tutorial will take you through its applications.

Where is Asymmetric Key Cryptography used?

Asymmetric key cryptography has found use in many authentication domains thanks to its thorough identity verification process. Some applications are as follows:

  • Digital signatures: Verification of document origin and signature authenticity is possible today thanks to asymmetric key cryptography.
  • TLS/SSL handshake: Asymmetric key cryptography plays a significant role in verifying website server authenticity, exchanging the necessary encryption keys required, and generating a session using those keys to ensure maximum security. Instead of the rather insecure HTTP website format.
  • Crypto-currency: Asymmetric key cryptography uses blockchain technology to authorize cryptocurrency transactions and maintain the integrity of its decentralized architecture.
  • Key sharing: This cryptography category can also be used to exchange secret keys for symmetric encryption since keeping such keys private is of utmost importance in its system.

Why is Asymmetric Key Cryptography Called Public Key Cryptography?

The lack of reliance on a single point of failure key is the main benefit of asymmetric key cryptography over symmetric encryption. The key used to decode the data is intended to be private and does not need to be shared because the key used to encrypt was already made public. Due of its openness, asymmetric key cryptography is sometimes known as public-key cryptography.

This contrasts with symmetric encryption, where the single key used for both encryption and decryption is supposed to be kept secret, hence called private key cryptography.

Now, have a look at the most widely used asymmetric key cryptography algorithm today.

What Is RSA Encryption?

RSA encryption is an asymmetric encryption algorithm named after its founders (Rivest, Shamir & Adleman) that uses block cipher methodology to encrypt data. It has been adopted worldwide in many industries like VPNs, chat applications, browser authorization, and email encryption, to name a few.


RSA algorithm is also used for the signing of documents, where the sender can sign a document using his own private key, and the receiver verifies the document using the sender’s public key. Since both keys are mathematically linked, it is impossible to replace either of the keys with a fraudulent piece.

In the next section, you will go through the reasons why asymmetric key cryptography is widely accepted today as one of the most secure and reliable forms of encryption.

What Are the Advantages of Using Asymmetric Key Cryptography?

Asymmetric encryption has a few advantages over symmetric encryption, which uses a single key for encryption and decryption of data. Some of these advantages are:

  • No key sharing: Asymmetric key cryptography overcomes the biggest flaw of symmetric key cryptography since it doesn’t need to exchange any keys that can decrypt data.
  • Proof of owner: Since it links the private and public keys together, a message is decrypted using a private key. It stands as evidence that the message originated from the rightful owner who has the private key.
  • Longer key lengths: Asymmetric encryption algorithms have key sizes up to 4096 bits that significantly increase the cipher and ciphertext security.
  • Tamper-proof: H4kers can’t modify data during transmission since doing so will prevent the receiver’s private key from decrypting the message, thus informing the receiver that the message has been meddled with.

What is Phishing Attack? Definition, Types and How to Prevent it

Phishing is a type of social engineering attack often used to steal user data, including login credentials and credit card numbers. It occurs when an attacker, masquerading as a trusted entity, dupes a victim into opening an email, instant message, or text message. The recipient is then tricked into clicking a malicious link, which can lead to the installation of malware, the freezing of the system as part of a ransomware attack or the revealing of sensitive information.

An attack can have devastating results. For individuals, this includes unauthorized purchases, the stealing of funds, or identity theft.

Moreover, phishing is often used to gain a foothold in corporate or governmental networks as a part of a larger attack, such as an advanced persistent threat (APT) event. In this latter scenario, employees are compromised in order to bypass security perimeters, distribute malware inside a closed environment, or gain privileged access to secured data.

An organization succumbing to such an attack typically sustains severe financial losses in addition to declining market share, reputation, and consumer trust. Depending on scope, a phishing attempt might escalate into a security incident from which a business will have a difficult time recovering.

Phishing attack examples

The following illustrates a common phishing scam attempt:

  • A spoofed email ostensibly from is mass-distributed to as many faculty members as possible.
  • The email claims that the user’s password is about to expire. Instructions are given to go to to renew their password within 24 hours.
Phishing attack example - Phishing email

Several things can occur by clicking the link. For example:

  • The user is redirected to, a bogus page appearing exactly like the real renewal page, where both new and existing passwords are requested. The attacker, monitoring the page, hijacks the original password to gain access to secured areas on the university network.
  • The user is sent to the actual password renewal page. However, while being redirected, a malicious script activates in the background to hijack the user’s session cookie. This results in a reflected XSS attack, giving the perpetrator privileged access to the university network.

How Does a Phishing Attack Work?

A phishing attack is usually a part of a large campaign, aiming to capture as many victims as possible in a big sample space of targets. Starting from its place of origin to the successful retrieval of credentials, a phishing attack consists of four independent phases that need to be executed. Let us learn more about each individual phase in detail, as denoted in the image below.


Phase 1: A malicious h4ker sends an email or a message to the target, acting as a reputed source. More often than not, it asks the target to follow a third-party link for a security inspection or a simple feature update.

Phase 2: The target thinks the email came from the mentioned sender, be it a bank or a company, and follows the malicious link to a counterfeit web page designed to look as similar as possible to an authentic website.

Phase 3: On the fake website, the user is asked to submit some private information, like account credentials for a specific website. Once the details are submitted, all the information is sent to the h4ker who designed the website and malicious email.

Phase 4: On receiving the account credentials, the h4ker is free to use them by logging in or selling consequent information retrieved on the internet to the highest bidder.

Now that you are aware of the different phases of a phishing attack. Let us learn about the various categories of phishing in our lesson on what is fishing.

What Are the Types of Phishing Attacks?


There are four types of phishing attacks:

  • Deceptive Phishing

In this category, a single phishing email is sent to a host of people, sometimes thousands, without much prior research. The h4ker hopes for a small percentage of people to click on the malicious link and divulge their private information on the fake website. 

  • Spear Phishing

In some cases, the h4kers conduct a minor amount of research to increase the chance of success in phishing attacks. If a person is known to order from Dominos pizzeria frequently, a phishing attack that acts as if it came from Dominos is more likely to be opened by the target instead of a random survey or newsletter.

  • Whaling

People of power like CEOs and administrative managers are often a target of phishing attacks that are meticulously planned and set up to guarantee a lapse in security. An extensive amount of research is done by the h4ker to decide on the manner and the appropriate time for these attacks.

  • Pharming

In pharming attacks, h4kers buy domain names adjacent to popular websites like or, hoping that a target will type such a URL in a hurry. When they reach the website, they see an identical web page to the original, submitting their login credentials without cross-checking the address.

Now that you learned about the different types of phishing attacks, look at the possible reasons why phishing attacks are likely to occur. 

Phishing techniques

Regardless of how they are targeted, phishing attacks take many roads to get to you and most people are likely to experience at least one of these forms of phishing:

  • Phishing email appears in your email inbox — usually with a request to follow a link, send a payment, reply with private info, or open an attachment. The sender’s email might be tailored to closely resemble a valid one and may contain info that feels personal to you.
  • Domain spoofing is a popular way an email phisher might mimic valid email addresses. These scams take a real company’s domain (ex: and modify it. You might engage with an address like “” and fall victim to the scheme.
  • Voice phishing (vishing) scammers call you and impersonate a valid person or company to deceive you. They might redirect you from an automated message and mask their phone number. Vishers will try to keep you on the phone and urge you to take action.
  • SMS phishing (smishing) similarly to vishing, this scheme will imitate a valid organization, using urgency in a short text message to fool you. In the message, you’ll usually find a link or a phone number they want you to use. Mobile messaging services are also at risk of this.
  • Social media phishing involves criminals using posts or direct messages to persuade you into a trap. Some are blatant like free giveaways or sketchy “official” organization pages with an urgent request. Others might impersonate your friends or build a relationship with you long-term before ‘attacking’ to seal the deal.
  • Clone phishing duplicates a real message that was sent previously, with legitimate attachments and links replaced with malicious ones. This appears in email but may also show up in other means like fake social media accounts and text messages.

In other cases, legitimate websites might be manipulated or imitated via:

  • Watering hole phishing targets popular sites that many people visit. An attack like this might try to exploit weaknesses in a site for any number of other phishing attacks. Delivering malware, link redirection, and other means are common in these schemes.
  • Pharming (DNS cache poisoning) uses malware or an onsite vulnerability to reroute traffic from safe websites to phishing sites. Manually typing a URL will still lead visitors to the malicious site if it is a victim of pharming.
  • Typosquatting (URL hijacking) tries to catch people who type an incorrect website URL. For example, a website might be created that is one letter off from a valid one. Typing “wallmart” instead of “walmart” could potentially lead you to a malicious site.
  • Clickjacking uses a website’s vulnerabilities to insert hidden capture boxes. These will grab user login credentials and anything else you might enter on the otherwise safe site.
  • Tabnabbing happens when an unattended fraudulent page reloads into an imitation of a valid site login. When you return to it, you might believe it to be real and unknowingly hand over access to your account.
  • HTTPS phishing gives a malicious website the illusion of security with the classic “padlock next to the URL bar” indicator. While this encryption sign used to be exclusive to sites that were verified as safe, now any site can get this. So, your connection and info you send may be blocked to outsiders, but you’re already connected to a criminal.

Even your actual internet connection can be compromised by:

  • Evil twin attacks mimic official public Wi-Fi at locations like coffee shops and airports. This is done in efforts to get you to connect and eavesdrop on all your online activity.

Finally, here are some more types of phishing you should be aware of:

  • Search engine results in phishing use methods to get a fraudulent webpage to appear in search results before a legitimate one. It is also known as SEO phishing or SEM phishing. If you don’t look carefully, you may click the malicious page instead of the real one.
  • Angler phishing impersonates a customer service representative for a real company to trick you out of information. On social media, a fake help account spots your “@mentions” to the company’s social handle and responds with a fake support message.
  • BEC (business email compromise) involves various means of breaching a company’s communications circle to get high-value info. This can include CEO impersonation or pretending a vendor with a fake invoice to initiate activities like wire transfers.
  • Cryptocurrency phishing targets those with cryptocurrency wallets. Instead of using long-term means to mine cryptocurrency themselves, these criminals try to steal from those that already have these funds.

The truth is the list of types of phishing attacks is extensive and constantly expanding. These are some of the most common currently, but you might see new ones even in a few months.

Since these scams rapidly change to fit current events, they’ve been hard to spot. But there are ways you can keep yourself safer and being aware of the latest scams is an easy way to start.

Some examples of common phishing scams

Whilst it would be impractical and impossible to list every known phishing scam here, there are some more common ones you should definitely look out for:

Iran Cyberattack phishing scams use an illegitimate Microsoft email, prompting a login to restore your data in an attempt to steal your Microsoft credentials. Scammers use your fear of being locked out of Windows and the relevance of a current news story to make it believable.

Office 365 deletion alerts are yet another Microsoft-related scam used to get your credentials. This email scam claims that a large volume of files has been deleted from your account. They give you a link to log in, of course, resulting in your account being compromised.

Notice from the bank. This scam tricks you with a fake account notification. These emails normally give you a convenient link that leads to a web form, asking for your bank details “for verification purposes.” Do not give them your details. Instead, give your bank a call as they may want to take action on the malicious email.

Email from a ‘friend’. This scam takes the form of a known friend who is in a foreign country and needs your help. This ‘help’ normally involves sending money to them. So, before you send your ‘friend’ money, give them a call first to verify whether it’s true or not.

Contest winner/Inheritance email. If you’ve won something unexpectedly or received an inheritance from a relative you’ve never heard of, don’t get too excited. Most of the time, these emails are scams that require you to click on a link to enter your info for prize shipment or inheritance ‘verification’.

The tax refund or rebate This is a popular phishing scam as many people have annual taxes which they pay or have to submit payments for. These phishing messages normally say that you are either eligible to receive a tax refund or have been selected to be audited. It then requests that you submit a tax refund request or tax form (asking for your full details), which scammers then use to either steal your money and/or sell your data.

How to prevent phishing

Phishing attack protection requires steps to be taken by both users and enterprises.

For users, vigilance is key. A spoofed message often contains subtle mistakes that expose its true identity. These can include spelling mistakes or changes to domain names, as seen in the earlier URL example. Users should also stop and think about why they’re even receiving such an email.

For enterprises, a number of steps can be taken to mitigate both phishing and spear phishing attacks:

  • Two-factor authentication (2FA) is the most effective method for countering phishing attacks, as it adds an extra verification layer when logging in to sensitive applications. 2FA relies on users having two things: something they know, such as a password and user name, and something they have, such as their smartphones. Even when employees are compromised, 2FA prevents the use of their compromised credentials, since these alone are insufficient to gain entry.
  • Employ common sense before handing over sensitive information. When you get an alert from your bank or other major institution, never click the link in the email. Instead, open your browser window and type the address directly into the URL field so you can make sure the site is real.
  • Never trust alarming messages. Most reputable companies will not request personally identifiable information or account details, via email. This includes your bank, insurance company, and any company you do business with. If you ever receive an email asking for any type of account information, immediately delete it and then call the company to confirm that your account is OK.
  • Do not open attachments in these suspicious or strange emails — especially Word, Excel, PowerPoint or PDF attachments.
  • Avoid clicking embedded links in emails at all times, because these can be seeded with malware. Be cautious when receiving messages from vendors or third parties; never click on embedded URLs in the original message. Instead, visit the site directly by typing in the correct URL address to verify the request, and review the vendor’s contact policies and procedures for requesting information.
  • Keep your software and operating system up to date. Windows OS products are often targets of phishing and other malicious attacks, so be sure you’re secure and up to date. Especially for those still running anything older than Windows 10.

What Is A DDoS Attack And How Can It Be Fended Off?

With work from home being the norm in today’s era, people spend considerable time on the internet, often without specific measures to ensure a secure session. Apart from individuals, organizations worldwide that host data and conduct business over the internet are always at the risk of a DDoS attack.

Now, begin by learning about what is a DDoS attack.


To understand how a DDoS attack works, you must know what a denial of service attack or a DOS attack is.

In a DOS attack, the h4ker seeks to make the resources of a particular server, database, or router inaccessible to its users. This can be done by clogging the available bandwidth of the target, be it via continuous web requests or indefinite ping commands. Analogous to how blocking a shop’s door prevent potential clients from entering it, DOS attacks were complete distress in the early days of network security

Distributed denial of service, or DDoS, is a technical term. DDoS attacks use several devices to attack a target, making it possible to track down the original h4ker, as opposed to one device targeting one server. A server outage occurs when there are too many devices trying to access a server’s resources, preventing authorized users from using them.

Now that you have learned what is a DDoS attack, take a look at how a DDoS attack works. 

How Does a DDoS Attack Work?

A DDoS attack is a two-phase process.

Phase 1: A network of devices is built by the h4ker. Simply said, malware, ransomware, or straightforward social engineering are used to compromise a large network of machines. These devices are part of a botnet network, which is always ready to launch an attack on a server or a system at the command of the h4ker who built the botnet. These computers are referred to as bots or zombies in this network.


Phase 2: When the h4ker finds the right time to attack, all the zombies in the botnet network send requests to the target, taking up all the server’s available bandwidth. These can be simple ping requests or complex attacks like SYN flooding and UDP Flooding.


You now have a general idea about how DDoS attacks work. Now, learn a little more about the various types of DDoS attacks.

Types of DDoS Attacks

  • Volume/Network-Based Attacks: These attacks focus on clogging all the available bandwidth for the server, cutting the supply short. Several requests are sent to the server, all warrant a reply, thereby not allowing the target to cater to general users. Example – ICMP echo requests and UDP floods.
  • Protocol-Based Attacks: These attacks are meant to consume essential resources of the target server. They exhaust the load balancers, and firewalls meant to protect the system against such DDoS attacks. Example – SYN floods and ping of death.
  • Application-Based Attacks: These are relatively sophisticated attacks that target application and operating system-level vulnerabilities. They prevent the specific applications from delivering the necessary information to users and hog the network bandwidth up to the point of a system crash. Example – HTTP flooding and BGP hijacking.
  • Fragmentation Attacks: This attack category involves a h4ker sending tiny fragments of web requests slower than usual. Since a server needs to receive all the fragments before moving on to a different request, getting stuck with a single request’s fragments takes up all the resources indefinitely. Example – Teardrop attack and ICMP flooding.

To better understand why DDoS attacks are so commonplace in today’s day and age, take a look at some of the aims a DDoS attack may have had when being launched.

Aim of DDoS Attacks

  • Competitive Advantage: H4king communities frequently launch DDoS attacks on adversarial organizations. To obtain an advantage on the field of play, some organizations employ such communities to network-level stagger the resources of their competitors. A company’s reputation suffers greatly as a result of a DDoS attack because it shows a lack of security and gives their competitors some cover.
  • Ransom Demands: Some h4kers launch these DDoS attacks to hold multinational companies at ransom. The resources are jammed, and the only way to clear the way is if the target company agrees to pay a designated amount of money to the h4kers.
  • Activist Behaviour: Certain activists tend to use DDoS attacks to voice their opinion. Spreading the word online is much faster than any local rally or forum. Primarily political, these types of attacks can also focus on online communities, ethical dilemmas, or even protests against corporations.

Now that you have a good understanding of the aim and working of DDoS attacks, you will learn some ways you can protect yourself from such attacks.

Prevention of DDoS Attacks

  • Load Balancers & Firewalls: Load balancers re-route the traffic from one server to another in a DDoS attack. This reduces the single point of failure and adds resiliency to the server data. Firewalls block unwanted traffic into a system and manage the number of requests made at a definite rate. It checks for multiple attacks from a single IP and occasional slowdowns to detect a DDoS attack in action.
  • Detection & Mitigation: Having a response plan for DDoS attacks is highly crucial. The sooner such a breach is noted, the easier it is to clear the clogging. One can also employ DDoS prevention tools like Imperva to lessen their load under high-pressure situations.
  • Switch to Cloud Service: With many organizations already aboard, cloud computing giants like Amazon web services (AWS) and Microsoft Azure have advanced DDoS protection tools in place. Furthermore, this eliminates the need for having a response plan to combat an attack since the engineers at the respective cloud providers will bear the brunt of the breach.

In the final topic of this lesson on what is a DDoS attack, you will see a live demo where a Linux system is breached with a DOS attack.

Live Demo

In this demonstration, you have two virtual machine instances. One of them is Parrot Security, which is typically utilized by h4kers to perform targeted assaults like DDoS on particular targets. Our target system, a common Linux distribution, is running in the second virtual machine. Due to its dependability and sparse resource requirements, Linux is used as the backend by the vast majority, if not all, of servers worldwide.

1. You have to set up a Wireshark program on our target system, which helps analyze the network traffic being sent and received from the instance.


2. To attack the target, you need to get its IP address, which acts as an identifier for the system. You can find the local IP address by using the command “ifconfig”.


3. To launch the attack, we will need a program called Hping3. It is a command-line tool that acts as a packet generator and analyzer for the TCP/IP protocol. You will use the IP address detected in the previous image to start the attack. The command to be given using hping3 is:


4. Once this command is run, you can watch the Wireshark window on our target system and watch a flurry of requests being sent from a single IP address. After a few seconds, the system becomes completely unresponsive due to the lack of processing power in handling so many requests simultaneously.


It was either a DoS assault or a straightforward denial of service attack that you just launched. Smaller attacks cannot bring down the massive servers used by large organizations. If several systems assault more complex and robust systems in the same way, they eventually succeed unless immediate action is taken. DDoS, or distributed denial of service, is the phrase used to describe a communication disruption caused by multiple systems.

SolarWinds Attack And All The Details You Need To Know About It

The COVID-driven epidemic has seen an all-time peak in cybercrimes. Ransomware assaults and trojan injection campaigns have targeted important IT industry players. One such instance is the 2020 SolarWinds attack, which is still having an impact on many consumers as of late 2021. According to estimates, the attack would infect more than 18,000 systems globally and will result in billions of dollars’ worth of irreparable harm.

Now, dive into this tutorial by learning about what SolarWinds is.

What Is SolarWinds?

The Tulsa, Oklahoma-based startup SolarWinds offers SaaS solutions for network administration, supply management, and IT infrastructure. They have complete access to client data, logs, and workflow information because they oversee IT infrastructure.

Let’s look into the main focus of this tutorial, the SolarWinds attack, and its origin.

How Did the SolarWinds Attack Happen?

SolarWinds offers an IT performance management and monitoring system called Orion. The Orion platform was used by customers worldwide. To enhance its effectiveness, Orion has access to customer system performance logs and data, making it a lucrative target for h4kers. This platform was a victim of a supply chain attack that affected thousands of systems and customers on a global scale.


Some features of the SolarWinds Orion Platform (Source: Solarwinds)

The h4kers used a supply chain attack to insert malicious pieces of code into the Orion framework. In a supply chain attack, malicious actors target third-party resources necessary for an organization’s workflow, preferably without the company’s direct jurisdiction.

In the Orion h4ck, a backdoor was created which could be accessed by the h4kers to impersonate accounts and users of victim organizations. This backdoor allowed the h4kers to access system files and hide their tracks by blending into the Orion activity, masking the malicious code from antivirus packages.

SolarWinds was a promising target for this kind of supply chain attack. Because many multinational companies and government agencies use their Orion software, all the h4kers needed was to install the trojan onto a new batch of updates to be distributed by SolarWinds.

Considering the widespread acceptance and usage of the Orion platform, SolarWinds was a potentially promising target. The software had found use in many multinational corporations and government agencies, allowing the h4kers uninterrupted access to confidential information after the SolarWinds update server distributed the malicious code.

The SolarWinds network had already been compromised by bad actors by late 2019. The backdoor was included in an update that was a remote access trojan (RAT). The Sunburst update was the name of this specific malicious update. By spring 2020, people were already receiving this damaging upgrade. Given that the update was obtained directly from the SolarWinds servers, users had no reason to be skeptical.

Now that you have learned how the SolarWinds h4k expanded, you can learn more about its detection and eventual fixes. 

How Was the H4ck Detected and Remedied?

FireEye, a cybersecurity company, detected the malware spreading to their customers and was able to identify the Sunburst update package responsible for the breach. Once detected, several customers could detect similar behavior in their systems and their customers, indicating a rapid spread of the malware package. First detected in late 2020, the Sunburst update had infected thousands of systems worldwide by then.

The SolarWinds development released quick hotfixes to eliminate the backdoor trojan and was eventually followed by a queue of organizations. Global IT giant Microsoft was also said to find traces of said malware in its customer systems, causing a global release of security patches.

Let us take a look at the primary victims of the SolarWinds Attack of 2020.

Who Was Affected by the H4ck?

The Sunburst update had been installed by more than 18,000 SolarWinds users, which gave the remote access trojan access to all of their users’ computers and networks. The US departments of health, treasury, and state were among the noteworthy victims of this attack.

Reports also indicated that private companies like FireEye, Intel, Cisco, and Microsoft are affected by this malware. As detected by Microsoft, the ability of this update to replicate into innumerable customer devices made it a challenge to estimate the headcount of affected organizations and networks.

As of now, there is no clear indication as to who was behind the entire attack. A few fingers have been raised over state-sanctioned h4kers in Russia and China, but the lack of concrete proof has left the door open for further investigations as well.

State of the SolarWinds H4ck in 2021

The SolarWinds attack’s aftereffects are still felt today. Several state attorneys’ Microsoft 365 accounts were compromised as recently as July 2021. A federal lawsuit was brought against the firm on the grounds that it misled shareholders about its security procedures prior to the Orion breach, given that the SolarWinds h4ck caused the parent company’s stock value to decline.

Every few weeks, a new problem arises due to the original h4ck. Be it confiscated email accounts or customers discovering new backdoors, the unauthorized access to systems opened up many issues that may take years to resolve.

In this tutorial on the SolarWinds attack, you learned about the parent company behind the software being breached, how h4kers leveraged weak security practices, the effects of the global h4ck, and the direct victims of the breach.

Attacks like the SolarWinds one are debilitating for organizations today, even the biggest ones, and they are continually seeking out expert professionals to help them safeguard their business. With Simplilearn’s Cyber Security Expert Master’s program, you can become the one they seek. An intense boot camp program designed by today’s top experts, it has been ranked as the Best Cybersecurity Bootcamp in 2021 in the recent list created by Course Report. Take a look—the comprehensiveness and the applied and engaging nature of the program is sure to get you excited.

If you have any questions regarding the SolarWinds h4ck, feel free to leave your queries in the comments box, and we will get back to you with an answer.


  • Cryptography is the science of ciphering and deciphering messages.
  • A cipher is a message that has been transformed into a nonhuman readable format.
  • Deciphering is reversing a cipher into the original text.
  • Cryptanalysis is the art of deciphering ciphers without the knowledge of the key used to cipher them.
  • Cryptology combines the techniques of both cryptography and cryptanalyst.
  • RC4 brute force online algorithm is used to create stream ciphers. It is mostly used in protocols such as Secure Socket Layer (SSL) to encrypt internet communication and Wired Equivalent Privacy (WEP) to secure wireless networks. 

Leave a Reply

Your email address will not be published. Required fields are marked *