What hashing algorithm does Windows 10 use to store passwords?

Question

I have recently been taught about hashing in A-Level Computing and wondered if I could write a program to hash passwords using the same algorithm as Windows 10.

The reason I want to use the same algorithm as used to store passwords in Windows 10 is because I would like to compare the hashed value I generate to the value stored by Windows.

What hashing algorithm does Windows 10 use to store passwords?

Solution

The NT hash is simply a hash. The password is hashed by using the MD4 algorithm and stored.

• https://technet.microsoft.com/en-us/library/hh994558(v=ws.10).aspx

NTLM [..] uses RC4 for encryption. Deriving a key from a password is as specified in RFC1320 and [FIPS46-2].

• https://msdn.microsoft.com/en-us/library/cc236715.aspx

This appears to still be the case in Windows 10, although it's now stored completely differently (in an isolated virtual machine for protecting passwords).

This reasoning also backs up the idea that the hash algorithm won't have changed, but it's not a certainty.

NB. that this applies to a standalone computer. If the computer is joined to an Active Directory domain, the domain controllers use an AES based system for password hashing.