# A report onCryptography

Practice and study of techniques for secure communication in the presence of adversarial behavior.

- Cryptography

## Cryptanalysis

Cryptanalysis (from the Greek kryptós, "hidden", and analýein, "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems.

Cryptanalysis (from the Greek kryptós, "hidden", and analýein, "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems.

Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown.

## Public-key cryptography

Cryptographic system that uses pairs of keys.

Cryptographic system that uses pairs of keys.

The generation of such key pairs depends on cryptographic algorithms which are based on mathematical problems termed one-way functions.

## Data Encryption Standard

Symmetric-key algorithm for the encryption of digital data.

Symmetric-key algorithm for the encryption of digital data.

Although its short key length of 56 bits makes it too insecure for modern applications, it has been highly influential in the advancement of cryptography.

## Block cipher

In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called blocks.

## Cipher

In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure.

## Ciphertext

In cryptography, ciphertext or cyphertext is the result of encryption performed on plaintext using an algorithm, called a cipher.

## Encryption

In cryptography, encryption is the process of encoding information.

## Diffie–Hellman key exchange

Method of securely exchanging cryptographic keys over a public channel and was one of the first public-key protocols as conceived by Ralph Merkle and named after Whitfield Diffie and Martin Hellman.

Method of securely exchanging cryptographic keys over a public channel and was one of the first public-key protocols as conceived by Ralph Merkle and named after Whitfield Diffie and Martin Hellman.

DH is one of the earliest practical examples of public key exchange implemented within the field of cryptography.