AES Advanced Encryption Standard
 A replacement for DES
 Fixed blocksize of 128
 Key sizes of 128, 192, 256 bits
 Different number of rounds for different key sizes.
 Algorithm:
 Round 1 Substitute
 Round 2 Shift
 Round 3 Mix
 Round 4 Add a Key

 It can still be implemented on basic hardware.
 It is estimated that 128 bit key would take billions of years with current and forseeable hardware.
 There have been some minor improvements in brute force.
 The best I can find is to cut the time by 1/4
 But this is still in the billions of years.
 Improvement over DES
 Both the keysize and rounds in DES are fixed.
 AES can be extended by changing either of these.
 I found it amusing that they warn about bad coding practices
 P 99: "Remember, of course, that these strength figures apply on if the implementation and use are robust; a strong algorithm loses strength if used with a weakness that lets outsiders determine key properties of the encrypted data."
 They state that DES and AES are up to 10,000 times faster than RSA
 Use RSA to exchange DES/AES keys
 Use DES/AES to exchange message.