Retrieving password when the password stored as a hash value

Question

Can users request that their password be emailed to themselves if the password is stored as a hash value?

Is there any way to convert a hash value to the clear text

Answer 1

There are different types of hashing algorithms. Some are more secure than others. MD5 is a popular, but insecure one. The SHA-family is another more secure set of algorithms.

By definition, a hash is a one way function. It can not be reversed.

http://en.wikipedia.org/wiki/Sha-1