Issues with DES

• The original (IBM) algorithm which was the basis of DES used a 128 bit key, changed by the the US government to a 56 bit key before it was issued as a standard. This made DES considerably less secure.
   
  
• Many people believe that the US government has a "backdoor" (or trapdoor) decryption technique which is infeasible at 128 bits, but possible with 56. This has never been confirmed, and is probably untrue.
   
  
• 56 bit DES is nowadays regarded as "relatively easily crackable". A variation called triple DES (3DES) uses either two keys (112 bits -- encrypt with the first key, then the second, then again with the first) or more commonly three keys (168 bits) and is still considered sufficiently secure for production use.
   
  
• Other common encryption algorithms in current use include 3DES, IDEA, Blowfish, RC2 and RC5. These are all considered to be appropriate for secure communications.
   
  
• The US Government has mandated (in 2000) a new encryption algorithm which is intended to replace DES, but it is apparently not yet in wide use.