Editing Cipher (section)

===Modern===
Modern encryption methods can be divided by two criteria: by type of key used, and by type of input data.

By type of key used ciphers are divided into:
* [[symmetric key algorithm]]s ([[Private-key cryptography]]), where one same key is used for encryption and decryption, and
* [[File:AES (Rijndael) Round Function.png|thumb]][[asymmetric key algorithm]]s ([[Public-key cryptography]]), where two different keys are used for encryption and decryption. 

In a symmetric key algorithm (e.g., DES and AES), the sender and receiver must have a shared key set up in advance and kept secret from all other parties; the sender uses this key for encryption, and the receiver uses the same key for decryption. The design of AES (Advanced Encryption System) was beneficial because it aimed to overcome the flaws in the design of the DES (Data encryption standard). AES's designer's claim that the common means of modern cipher cryptanalytic attacks are ineffective against AES due to its design structure.

Ciphers can be distinguished into two types by the type of input data:
* [[block cipher]]s, which encrypt block of data of fixed size, and
* [[stream cipher]]s, which encrypt continuous streams of data.