4 ms·

From what I understand they assume a user database with md5-hashed passwords may have leaked. Now md5 is outdated, bad and was never made for passwords, but st

by hannob 6y ago

From what I understand they assume a user database with md5-hashed passwords may have leaked. Now md5 is outdated, bad and was never made for passwords, but still, there's no easy way to simply invert md5. So for this to have happened, the password must've been bruteforced. Which is only practically possible if it was a weak password. Which makes me think maybe that's not what happened and maybe the real culprit is password stuffing. If someone had a password weak enough that bruteforcing is plausible then maybe that person also used the password for another service.

jiggawatts 6y ago
> Which is only practically possible if it was a weak password. Back in 2016, hashcat could achieve 200 billion hash crack attempts per second on commodity hardware: https://gist.github.com/epixoip/a83d38f412b4737e99bbef804a270c40 https://gist.github.com/epixoip/a83d38f412b4737e99bbef804a27... That can crack all alphanumeric 8-character passwords in 18 minutes, and all 9-character alphanumeric+symbol passwords in just 10 days! Then consider that there are precomputed rainbow tables that have had far more computer power thrown at them, and suddenly MD5 starts looking more like a "light obfuscation" than a true cryptographic hash...
- gruez 6y ago
  >Then consider that there are precomputed rainbow tables that have had far more computer power thrown at them, and suddenly MD5 starts looking more like a "light obfuscation" than a true cryptographic hash... ...because that's not what a cryptographic hash means. SHA256, a "secure" hash is vulnerable to the same things you mentioned. The term you're looking for is a password hash, or a key stretching function, which is intentionally slow to be resistant to brute-forcing. As for rainbow tables, that's solved at the application level with salts.
  - hu3 6y ago
    Yep. I think current PHP best practice is to use standard library password_hash() and password_verify() which takes care of salting: https://www.php.net/manual/en/function.password-hash.php https://www.php.net/manual/en/function.password-hash.php

by hannob 6y ago

jiggawatts 6y ago

> Which is only practically possible if it was a weak password. Back in 2016, hashcat could achieve 200 billion hash crack attempts per second on commodity hardware: https://gist.github.com/epixoip/a83d38f412b4737e99bbef804a270c40 https://gist.github.com/epixoip/a83d38f412b4737e99bbef804a27... That can crack all alphanumeric 8-character passwords in 18 minutes, and all 9-character alphanumeric+symbol passwords in just 10 days! Then consider that there are precomputed rainbow tables that have had far more computer power thrown at them, and suddenly MD5 starts looking more like a "light obfuscation" than a true cryptographic hash...

gruez 6y ago
>Then consider that there are precomputed rainbow tables that have had far more computer power thrown at them, and suddenly MD5 starts looking more like a "light obfuscation" than a true cryptographic hash... ...because that's not what a cryptographic hash means. SHA256, a "secure" hash is vulnerable to the same things you mentioned. The term you're looking for is a password hash, or a key stretching function, which is intentionally slow to be resistant to brute-forcing. As for rainbow tables, that's solved at the application level with salts.
- hu3 6y ago
  Yep. I think current PHP best practice is to use standard library password_hash() and password_verify() which takes care of salting: https://www.php.net/manual/en/function.password-hash.php https://www.php.net/manual/en/function.password-hash.php