Table Key Presentation

Length in bits, hex characters and bytes for different key lengths of typical symmetric encryption methods:

Bit length (2^n) n Number of bytes (bit length: 8) Number of hex characters (bit length: 4) Example
32 5 4 8  
56   7 14 DES
64 6 8 16 RC4
112   14 28 Triple-DES
128 7 16 31 IDEA, AES
196   24 48 AES
256 8 32 64 AES