SingleKey.md (893B)
1 # Single Key (Cryptography) 2 3 **Source:** Cryptography and Network Security 4 5 **Chapter:** 1.6 6 7 **Definition:** Single key cryptography is data transformation that uses only a singular key in the transformation process. 8 9 ### Types 10 11 Two common symmetric encryption algorithm types are block cipher and stream cipher. 12 13 #### Block Cipher 14 15 Block cipher symmetric encryption involves getting a block of data with a predefined size and then running an algorithm to transform the data. 16 17 #### Stream Cipher 18 19 Stream cipher symmetric encryption often involves XORing the incoming data with a symmetric key. By doing this we don't need to wait for an entire block before encrypting data. 20 21 #### Message Authentication Code (MAC) 22 23 A MAC is data associated with a block or message. A MAC is used to verify the integrity of a message. 24 25 Define f : (D, k) -> MAC where D is the data and k is the symmetric key.