Take the 2-minute tour ×  what are the applications of multiple
encryptions? where the multiple encryption like double DES and
triple DES algorithms are use?  share|improve this question
Double DES is vulnerable to meet-in-the-middle, don't use it:
en.wikipedia.org/wiki/Meet-in-the-middle_attack –  buherator Sep
10 '13 at 16:45  2 Answers 2  up vote 1 down vote accepted  3DES
tries to cope with the biggest weakness of DES, which is its
short key. A DES key contains only 56 useful bits, which makes
it amenable to exhaustive search. This has been demonstrated as
early as 1998.  Cascading two or three instances of the
algorithms, with distinct keys, is a fix which was easy to apply
on hardware which already included some DES circuitry. Moreover,
3DES has been especially designed so that it can be "DES-
compatible": since 3DES is "encrypt-decrypt-encrypt", it
suffices to make all three DES keys identical to obtain the same
result as plain DES.  3DES remains in active use in a lot of
legacy systems, and also in man