Hash Bash

On 18-Feb-2023 13:41:07:

I'm sure this isn't exactly news to Windows sysadmins, but as a Linux user I was just shocked to find out that Microsoft hasn't changed the Windows password hashing algorithm since the very first release of Windows NT in 1993. What is that algorithm? Unsalted MD4!

I wanted to see just how bad that actually was in a similar format to the nice infographics that Hive Systems made for MD5. So I made difficulty table generator. Here is the table for MD4 on an RTX 4090:

Some notable things:

• At least on a GPU cracker, the 1979 UNIX DES hash (first released with System 7) is stronger than the 1993 Windows MD4 hash for any given password complexity.
• Although weak by modern standards, the 1995 UNIX MD5 hash (designed by Poul-Henning Kamp for FreeBSD) is notably stronger than plain MD5. (The original UNIX DES hash appears to also be stronger than plain MD5!)
• Raw hash power (what is shown in these tables) is not the full story on algorithm strength. DES's Achilles Heel was the 8 character maximum length. Salting passwords also increases the strength in ways not shown in these tables.
• Windows Lan Manager hashes were two independent 7 character DES hashes and case insensitive, which results in a pretty unique table.
• All hail bcrypt!