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Encryption
Ciphers
| Ciphers | Description | Example |
| Block Cipher | Break messages into fixed length blocks, and encrypt each block using the same key | (3)DES, AES/Rijndael, IDEA |
| Stream Cipher | Break message into fixed length blocks, but use a sequence of keys to encrypt the blocks | Vigenère cipher, RC4, SEAL |
| Stream Cipher | Description |
| Synchronous Stream Ciphers | generates the key string from a source other than the message itself |
| Self-Synchronous Stream Ciphers | obtain a key from the message itself |
| Modes of Operation | Descriptions | Examples |
| Electronic Codebook Mode (ECB Mode) | | |
| Cipher-Block Chaining Mode (CBC Mode) | | |
| Counter Mode (CTR Mode) | | |
| Output Feedback Mode (OFB Mode) | | |
Common Terms
| DES | Data Encryption Standard |
| AES | Advanced Encryption Standard |
| plaintext | the original message |
| ciphertext | the coded message |
| cipher | algorithm for transforming plaintext to ciphertext |
| key | info used in cipher known only to sender/receiver |
| encipher (encrypt) | converting plaintext to ciphertext |
| decipher (decrypt) | recovering ciphertext from plaintext |
| cryptography | study of encryption principles/methods |
| cryptanalysis (codebreaking) | the study of principles/ methods of deciphering ciphertext without knowing key |
| cryptology | the field of both cryptography and cryptanalysis |
