Cipher

Cipher

Cipher, in the computer security context, refers to a cryptographic algorithm which is used to encrypt and decrypt electronic data. The procedure of encryption is the process of converting plain text data (readable text) to ciphertext (non-readable text) to prevent unauthorized access. Likewise, decryption is the process of converting ciphertext back to plain text.

Synonyms for a cipher include Encryption algorithm, Cryptosystem, and Cryptographic algorithm.

Ciphers are used to provide confidential communication between two or more parties. They can also be used for digital signature and authentication of digital documents. Examples of ciphers include AES (Advanced Encryption Standard), 3DES (Triple-DES), RSA (Rivest, Shamir, and Adelman), and RC4 (Rivest Cipher 4).

Ciphers are usually categorized into two main categories: symmetric encryption and asymmetric encryption. Symmetric encryption is also known as private key cryptography and uses the same key for encryption and decryption. Examples of symmetric ciphers include AES, RC4, and 3DES. Asymmetric encryption, on the other hand, uses two keys: one for encryption and one for decryption. Examples of asymmetric ciphers include RSA and Diffie-Hellman.

In addition, there are also various modes of operations which can be used with a cipher. These include Cipher Block Chaining (CBC), Counter (CTR), and Galois/Counter Mode (GCM). Each mode offers different security and efficiency depending on the situation.

Ciphers can also be classified based on their strength. Ciphers with short key lengths are considered weak ciphers and can be easily broken. On the other hand, ciphers with longer key lengths are considered strong ciphers and require more computational power to break.

Cipher is an essential element in computer security and is used in various applications such as websites, mobile devices, and communication systems. It is important to use strong ciphers and to keep them updated as new methods of attacks are constantly being developed.