man 3 crypt clearly states that it uses DES. I thought DES was deprecated, but I see no notice that crypt would be deprecated.Why does it not use AES instead, and is crypt(3) deprecated?Is it simply a case of DES is secure enough for the purpose of this library, and that programs should use other libraries for encryption of important stuff?
Why does crypt(3) use DES?
cryptography;crypt
crypt is easily breakable (it was in fact written by Robert Morris, a famous contributor to the early Unix, as a workbench for codebreaking activities) and should not be used for anything important.From the crypt manpage:The DES algorithm itself has a few quirks which make the use of the crypt() interface a very poor choice for anything other than password authentication.  If you are planning on using the crypt() interface for a cryptography project, don't do it: get a good book on encryption and one of the widely available DES libraries.For any real-world use, there are cryptographically stronger alternatives available, such as mcrypt and ccrypt (which uses AES). 