Which of the .NET included hashing algorithms are suitable for password hashing?

13
votes

The password leak of LinkedIn proved how important it is to securely hash your passwords. However, even hashing passwords with a salt is not secure with the 'normal' hashing algorithms (such as MD5 and the SHA family), since they are optimized for speed, which allows hackers compute 2300 million hashes per second (brute force).

There are hashing algoritms that are safer to use because they are much more computational intensive, such as PBKDF2, Bcrypt, PBMAC, and scrypt. These hashing algorithms however, don't seem to be included in the .NET framework.

So, which performance intensive hashing algorithms are included in the .NET framework?

ANSWER: PBKDF2 is included in the framework and this site shows how to use it properly.

3
c#.netsecurityhash
Interesting question, I was wondering the same thing because of the same reasons. :) – pyrocumulus
Nothing is "Secure". What you choose for security will always be a trade off with other requirements like speed, memory usage, CPU utilization, etc.. What you consider "secure enough" is based on your requirements--which you haven't provided. – Peter Ritchie
@PeterRitchie: That's why I'm refering to "hashing algoritms that are safer to" and that's what the question is about. – Steven
@Peter Ritchie While I'm usually all with the 'roll your own' attitude; in the case of a hash function, or anything security related, I'd highly advise against unless you really know what you are doing. Just sayin' ;) – pyrocumulus
Why is this question closed? There are a finite number of hashing algorithms included in the .NET framework and their relative suitability to password hashing is fairly objective. – Samuel Edwin Ward

3 Answers

12
votes

I think it's not really a meaningful Class name, but I do think it is included in the .NET framework. According to multiple sources, Rfc2898DeriveBytes is actually a PBKDF2 implementation. MSDN says so as well.

See Why do I need to use the Rfc2898DeriveBytes class (in .NET) instead of directly using the password as a key or IV? and PBKDF2 implementation in C# with Rfc2898DeriveBytes

for example.

-1
votes

There is no hashing algorith that is 100% secure. The linkedin hack was more due to infrastructure/code security than the hashing algorithm. Any hash can be calculated, it just takes longer the more complicated the hashing algortihm is. Some attacks such as collision attacks are not actually much slower to accomplish on a more complicated hash.

I always ensure that i hash passwords (never just encrypt), restrict access to servers. All developers workingfor me understand at least the basics of security (sql injection, overflows etc) and any high profile site i work on is pen-tested.