I work in C# and MSSQL and as you'd expect I store my passwords salted and hashed.
When I look at the hash stored in an nvarchar column (for example the out the box aspnet membership provider). I've always been curious why the generated Salt and Hash values always seem to end in either one or two equals signs.
I've seen similar things while working with encryption algorithms, is this coincidence or is there a reason for it?
These hashed string are (usually?) coded in the Base64 format and the equal sign are used for padding the string to make the length (number of bytes) divisible by three. Wikipedia explains it pretty well: http://en.wikipedia.org/wiki/Base64.
Could it be Base 64 encoding padding?
The '==' sequence indicates that the last group contained only one byte, and '=' indicates that it contained two bytes. The example below illustrates how truncating the input of the whole of the above quote changes the output padding:
