title: List of cryptosystems
text: # List of cryptosystems
  
  A cryptosystem is a set of cryptographic algorithms that map ciphertexts and plaintexts to each other.
  
  ## Private-key cryptosystems
  
  Private-key cryptosystems use the same key for encryption and decryption.
  
  * Caesar cipher
  * Substitution cipher
  * Enigma machine
  * Data Encryption Standard
  * Twofish
  * Serpent
  * Camellia
  * Salsa20
  * ChaCha20
  * Blowfish
  * CAST5
  * Kuznyechik
  * RC4
  * 3DES
  * Skipjack
  * Safer
  * IDEA
  * Advanced Encryption Standard, also known as AES and Rijndael.
  
  ## Public-key cryptosystems
  
  Public-key cryptosystems use a public key for encryption and a private key for decryption.
  
  * Diffie–Hellman key exchange
  * RSA encryption
  * Rabin cryptosystem
  * Schnorr signature
  * ElGamal encryption
  * Elliptic-curve cryptography
  * Lattice-based cryptography
  * McEliece cryptosystem
  * Multivariate cryptography
  * Isogeny-based cryptography
  