Timeline for Do salts have to be random, or just unique and unknown?

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May 15 at 22:55	comment	added	Ja1024		The purpose of salts is not to hide weak passwords or to mask the fact that multiple accounts use the same password. An attacker can easily find this out by simply trying common password choices or checking whether a found password also works for other hashes. Salts prevent an attacker from reusing hash calculations across accounts. If they want to try m passwords on n accounts, they have to do m * n calculations. Without salts, they would only need m calculations whose results can be compared against all hashes. Salts also prevent precomputed hash tables, but this is a secondary effect.
May 15 at 22:49	comment	added	Ja1024		It seems absurd to think that attackers will give up just because they cannot immediately see all accounts with the password "123456" due to salts. Nothing prevents them from simply trying this password (and other common choices) on all hashes. This is extremely cheap computationally, even in the case of modern password hashing algorithms like Argon2. So an attacker will most definitely find the accounts with very weak passwords, regardless of whether or not salts are used.
May 15 at 18:28	history	edited	gnasher729	CC BY-SA 4.0	added 263 characters in body
Jan 26 at 16:58	history	answered	gnasher729	CC BY-SA 4.0