## What is a secret key algorithm?

Secret key algorithms use the same key for encryption and decryption (or the decryption key is easily derived from the encryption key), whereas public key algorithms use a different key for encryption and decryption, and the decryption key cannot be derived from the encryption key.Secret-key algorithms are generally much less computationally intensive than public key algorithms.

## Types of secret key algorithms

Secret key algorithms can be divided into two types – stream ciphers and block ciphers. Stream ciphers encrypt a single bit of plaintext at a time, whereas block ciphers take a number of bits (typically 64 bits in modern ciphers), and encrypt them as a single unit.

**Secret key algorithms:**

– AES/Rijndael

– Blowfish

– CAST5

– DES

– IDEA

– RC2

– RC4

– RC6

– Serpent

– Triple DES

– Twofish