What are the Different Types of Encryption? List you must Know

Encryption is a security term that holds one of the most important security pillars which is confidentiality. It is a technique for transforming information on a computer in such a way that it becomes unreadable. So, even if someone is able to gain access to a computer with personal data on it, they likely won’t be able to do anything with the data unless they have complicated, expensive software or the original data key. 


The basic function of encryption is essentially to translate normal text into ciphertext. Encryption can help ensure that data doesn’t get read by the wrong people, but can also ensure that data isn’t altered in transit, and verify the identity of the sender. 


Encryption has evolved through the ages to be in the most mature form nowadays which is called advanced encryption. There are many types of encryption nowadays used for different applications, and that’s what we will be discussing in this article.

What is Encryption?

Encryption is a way of communication security. Communication in its original form (plaintext) is encrypted into an unintelligible form (ciphertext) using an encryption algorithm and a variable known as a key; the ciphertext is then transformed (decrypted) back into plaintext using the encryption algorithm and a key.


Many technological solutions to computer and communications security challenges rely on encryption. 

What is the History of Encryption?

Each time period includes multiple types of encryption reflecting its usage. In 742 BC, the Ancient Greeks invented the scytale where messages were written on strips of paper and only made sense if the paper was wound around a stick of the correct length and diameter.


In 50 BC, Julius Caesar used a shift cipher system. Later on, it is known as the Caesar cipher. The basic method is still used today.


In 1476, the Alberti -the first substitution cipher- was invented in Italy.


In 1586, the supporters of Mary, the Queen of Scots, used coded letters to plot Queen Elizabeth’s assassination. Fortunately, her spies were able to decipher the code, and Mary was dealt with. 


AD 800 - 900, Arabian mathematicians are the first to write down the theories of cryptography. 


In the modern world especially in 1797, Thomas Jefferson invented a wooden cylinder with several wheels. The letters of the English lexicon were printed on each wheel. Each wheel has to be in the correct position for the message to be read off the cylinder. 


From 1789 to 1815, Napoleon developed ciphers to transmit sensitive military information.


From 1938 to 1945, the work of Alan Turing, during the Second World War, was viewed as one of the reasons the allies won the war in 1945. This is because the allies were able to figure out the German ciphers in order to read their secret messages.


In 1961, the first computer password was created at the Massachusetts Institute of Technology to keep students from wasting time on computers.


In 1995, the term ‘hacker’ was used to describe someone who breaks into a computer system illicitly. It was originally used to describe a person hired to find errors in computer companies’ programs. 


Today, cryptography is used on a wide range of personal and public applications.

What is the difference between Symmetric and Asymmetric Encryption?

There are two types of encryption depending on if the key used in encryption is the same as the key used in decryption or not. If the same key is used, encryption is called Symmetric. If different keys are used, the encryption is called asymmetric. 


Asymmetric encryption is a technique that generates two keys: a private and a public key. These keys are not identical, because the public key can be shared with anybody, whilst the private key is only shared with individuals who need access to the data. You can encrypt data with either of the keys, and the decryption key is the inverse.


Symmetric encryption is a commonly-used technique where the encryption key and the decryption key are the same. It takes polynomial and therefore very little money for a computer to create a relatively strong, small key based on the algorithm it uses to encrypt data. Thereafter, the key is transmitted to the end-user, who uses it for decryption.


Both types of encryption are used in different application areas depending on data sensitivity and protocol of data transmission.  

Why is Data Encryption Necessary?

Encryption is required because it allows us to convey relevant and frequently sensitive information over the internet and via electronic means without it being seen by unauthorized parties. 


A key, which only authorized users will have, is required to decrypt the data. Keep in mind, however, that even encrypted data can be deciphered by people with the necessary abilities or resources, some of whom may be acting maliciously. 


Each type of encryption covers an area of application. Some types of encryption are complex and take time to run but are very secure. Other types of encryption are very simple and run very fast but are less secure.


Using different types of encryption depends on the application and the importance of data encrypted.

How is Encryption Used?

The sender must determine which cipher will best obscure the message's contents and which variable to use as a key to making the encoded message unique at the start of the encryption process. Asymmetric and symmetric encryption algorithms are the most often used forms of ciphers.


Because the sender or computing system encrypting the communication must share the secret key with all entities allowed to decode the message, the key is frequently referred to as a shared secret.


Asymmetric encryption is typically slower than symmetric key encryption. The Advanced Encryption Standard (AES), which was created to secure government-classified information, is the most extensively used symmetric key cipher.


Asymmetric cipher is called public-key encryption since it uses a public key that is shared publicly to all parties, and private key encryption that is owed by only the party that will receive the message. It encrypts data with two distinct but logically related keys.


Because factoring huge prime numbers and reverse-engineering the encryption is computationally challenging, this sort of cryptography frequently employs prime numbers to generate keys. 


The Rivest-Shamir-Adleman (RSA) encryption technique is the most extensively used public-key encryption method at the moment. The public or private key can be used to encrypt a message in RSA, and the key that is not used for encryption becomes the decryption key.

How does Data Encryption Work?

Encryption is a technique to alter the form of text into another form of unreadable text called ciphertext. This process requires three elements; input text, a key that encrypts the text, and the algorithm that transfers the plain text to ciphertext.


However, Decryption takes the inverse of the encryption algorithm, ciphertext, and the key which will be the same in the case of symmetric and not the same in the case of asymmetric.


In the case of asymmetric decryption, the key is generated by an algorithm.  The encryption security key's length determines the encryption strength. 


There are multiple types of encryption, each encryption has a technique of encryption and generation keys. 

Types of Encryption Methods and Techniques


Each type of encryption has an application and a story behind its development. A very common type of encryption is Advanced Encryption Standard (AES). 


The Advanced Encryption Standard (AES) is a symmetric block cipher designed to replace DES as the industry standard for a variety of applications. 


3DES' disadvantages include its slowness and the fact that it employs the same 64-bit block size as DES. A larger key size is advantageous in terms of both efficiency and security. As a result, the National Institute of Standards and Technology (NIST) has requested submissions for a new AES that should be as secure as or better than 3DES while also being much more efficient. 


AES must be a symmetric block cipher with a block length of 128 bits and key lengths of 128 bits, according to NIST. The encryption technique accepts a 16-bit block of plaintext as input and generates a 16-bit block of ciphertext as output using a 16-bit key.


The S-AES decryption algorithm takes a 16-bit block of ciphertext as input, together with the same 16-bit key that was used to create that ciphertext, and outputs the original 16-bit block of plaintext. Add key (AK), nibble substitution (NS), shift row (SR), and mix column are the four functions of transformations used in the encryption algorithm (MC).


There are three rounds to the encryption algorithm. Round 0 is just an add key round, round 1 is a full round with four functions, and round 2 only has three. The add key function, which uses 16 bits of key, is included in each round. The initial 16-bit key is enlarged to 48 bits, resulting in a unique 16-bit round key for each round.


Another type of encryption is DES. In general, all types of encryption are designed for a specific purpose. The DES cipher was developed as part of an IBM research initiative in the late 1960s that resulted in the LUCIFER cipher.


The decision to commercialize LUCIFER was made in the early 1970s, and a number of substantial changes were made. IBM was not the only one participating in these alterations, as they sought technical help from the National Security Agency (NSA), other outside experts were also involved although the NSA was most certainly the key technical contribution. 


The National Bureau of Standards requested that the revised version of LUCIFER be submitted as a proposal for a new national encryption standard (NBS). The Data Encryption Standard, or DES, was finally approved in 1977. (FIPS PUB 46).


Even to this day, some of the adjustments made to LUCIFER have sparked debate. The key size was the most prominent of these. The key size for LUCIFER was 128 bits, however, for DES it was decreased to 56 bits.


DES requires a 64-bit key as input, but the additional eight bits are utilized for parity checking and have no effect on the security of the algorithm. Because of its tiny size, outsiders believed the 56-bit key would be an easy target for a brute force attack. The necessity of the parity checking technique was also questioned, but no satisfactory responses were provided.


DES encryption of a communication block occurs in 16 steps or rounds. Once per round, sixteen 48-bit keys are created from the input key. Eight S-boxes are utilized in each round. These S-boxes are defined in the standard's specification. Six-bit groups are mapped to four-bit groups using S-boxes.


The National Security Agency of the United States has determined the contents of these S-boxes (NSA). The S-boxes appear to be filled at random, but this is not true. It was recently discovered that these S-boxes, which were first discovered in the 1970s, are resistant to a technique called differential cryptanalysis, which was first discovered in the 1990s.


The message's block is split in half. A second fixed table is used to enlarge the right half from 32 to 48 bits. Using the XOR technique, the result is merged with the round's subkey. The 48 bits are then changed to 32 bits using S-boxes, and then permutated once again using a fixed table. 


The XOR technique is used to merge the right and left halves, which have been completely shuffled. This combination becomes the new left half in the following round.

List of Encryption Algorithms

All types of encryption have different algorithms. Each algorithm has its pros and cons. Some algorithms take time to run and others do not. It is a trade-off between the resources used and the level of security.

1. Symmetric Algorithms 

It uses the same key to encrypt and decrypt data and includes: 

a- DES Symmetric Encryption Algorithm

b- AES Symmetric Encryption Algorithm

c- 3DES Symmetric Encryption Algorithm

2- Asymmetric Encryption 

It takes time to run but has a more rigid concept and higher security and includes: 

a- RSA Asymmetric Encryption Algorithm

b- The Advantage of Using the RSA Encryption Algorithm

PROS and CONS of Symmetric and Asymmetric Encryption

All types of encryption do the same functionality of changing the data form into an unreadable form to protect the confidentiality of the data.


However, types of encryption have different techniques. Each technique has its pros and cons. Both types of encryption; Symmetric and Asymmetric have different pros and cons. 


Symmetric Encryption: Symmetric cryptography's key benefit is its efficiency. Symmetric encryption techniques, on average, consume less memory and processing resources than asymmetric encryption algorithms.


Asymmetric Encryption: Asymmetric encryption does not necessitate the secure sharing of a secret key between the two parties prior to delivering encrypted messages. This allows you to communicate securely with anyone as long as you have their private key.


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