Encryption Algorithms
Tags: Information Technology, Computer Science, Network Security, Algorithms, Encryption

In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. This blog covers a brief history of encryption and different types of encryption algorithms.

History

Early Cryptographic methods were often utilized in the military. Since then, new methods have emerged and become commonplace in all areas of modern cryptography.

One of the most famous military encryption developments was the Caesar Cipher, which was a system in which a letter in the normal text is shifted down a fixed number of positions down the alphabet to get the encoded letter. A message encoded with this type of encryption could be decoded with the fixed number on the Caesar Cipher.

Arab mathematicians developed the method of frequency analysis which was an attempt to crack Caesar ciphers. This technique looked at the frequency of letters in the encrypted message to determine the appropriate shift.

Thomas Jefferson also proposed cipher to encode and decode messages in order to provide a more secure way of military communication. The cipher today is known as the Wheel Cipher or the Jefferson Disk, although never actually built, was theorized as a spool that could jumble an English message up to 36 characters. The message could be decrypted by plugging in the jumbled message to a receiver with an identical cipher.

A similar device to the Jefferson Disk named the M-94 was developed in 1917 by US Army Major Joseph Mauborgne. This device was used in U.S. military until 1942.

In World War II, the German Nazzi used an advanced version of the M-94 called Enigma.

Types of Encryption Algorithms

The process of encryption and decryption involves keys. Two main types of keys in cryptographic systems are symmetric-key and public-key (also known as asymmetric-key). Hence encryption algorithms can be classified among these 2 types.

Symmetric Key

In symmetric-key cryptography, the encryption and decryption keys are the same. Communicating persons must have the same shared key in order to achieve secure communication. The German Enigma Machine utilized a new symmetric-key each day for encoding and decoding the messages.

Asymmetric Key

In public-key encryption( Asymmetric) schemes, the encryption key(public key) is published for anyone to use and encrypt messages. However, only the receiving person has access to the decryption key(private key) that enables messages to be read.

The following picture clears the understanding of public-key cryptography and shared key cryptography.

Symmetric key cryptographic algorithms

1. AES

The Advanced Encryption Standard (AES) is the algorithm which is trusted as the standard by the U.S. Government and many organizations.

It is extremely efficient in 128-bit form, But AES also uses keys of 192 and 256 bits for heavy-duty encryption of messages.

AES is considered immune to all attacks, with the exception of brute force, which attempts to decipher messages using all possible combinations in the 256, 192, or 128-bit cipher. Security experts believe that AES will eventually be considered as standard for encrypting data in the private sector.

2. Blowfish

Blowfish is an algorithm designed to replace the Data Encryption Standard (DES). This symmetric cipher splits messages into blocks of 64 bits. and the blocks are encrypted individually.

Blowfish is known for both its speed and overall effectiveness as many claim that it has never been defeated. Although, Vendors have taken advantage of its free availability in the public domain.

Blowfish is found in categories ranging from e-commerce Websites for securing payments to password management tools, where it used to protect passwords. It’s definitely one of the more flexible encryption methods available today.

3.DES

The DES satisfies two of the desired properties of a block cipher. These two properties make this cipher very strong.

Avalanche effect − A small change in plaintext makes up a great change in the ciphertext.

Completeness − Every bit of ciphertext is dependant upon many bits of the plaintext.

In the recent past, cryptanalysis has found some weaknesses in Data Encryption Standard (DES) when the key selected is weak. These keys should be avoided.

Data Encryption Standard (DES) has proved to be a well-designed block cipher. There are no cryptanalytic attacks on DES other than intense key search.

Asymmetric key cryptographic algorithms

1. RSA

RSA is a public-key encryption (Asymmetric Key) algorithm and the standard for encrypting data sent over the internet. It is also one of the methods used in our PGP and GPG programs.

RSA is considered an asymmetric algorithm due to its use of a pair of keys. We have a public key, which is what we use to encrypt our message, and a private key to decrypt the messages. and no vice versa is allowed. The result of RSA encryption is a random bunch of characters that takes attackers a long time and processing power to break.

2.DSA

DSA refers to a standard for digital signatures. DSA was introduced in 1991 by the National Institute of Standards and Technology (NIST). And was proposed as a better method of creating digital signatures. Today DSA Along with RSA is considered one of the most preferred digital signature algorithms.

The Future of Encryption

Cyber attacks are constantly improving, so security personals must stay busy concocting new techniques to keep away. Experts are hopeful that a new method called Honey Encryption will deter hackers by giving up fake data for every incorrect guess of the key code and faking the failure. This approach slows down the attackers as well as potentially buries the correct key in a haystack of false hopes. Also, there are promising methods like quantum key distribution, which shares keys embedded in photons over the fiber optic, with all these new technology face of encryption is changing.