Bans work on identifiers — a license, a Discord ID, a hardware token. All of those can be changed, and someone determined enough will change them. Ban evasion is the reason a server that bans plenty of cheaters can still feel overrun by the same ones.
Fingerprinting is how Asphyxia recognises them anyway.
The idea
A player’s account is easy to replace. Their machine is not.
Asphyxia collects a set of harmless characteristics from each client — things like graphics hardware, screen properties, installed fonts, timezone and audio device counts. None of them identifies a person. Together, though, they form a profile that’s fairly distinctive, and that stays much the same when someone makes a new account on the same computer.
When a player joins, Asphyxia compares their profile against the profiles of players it has already banned. A close enough match is treated as ban evasion, and the returning player is banned again.
Confidence, not certainty
Matching is scored rather than exact. Two different people can share a lot of characteristics — the same laptop model, the same country, the same monitor — so a partial match means nothing on its own.
Asphyxia only acts on a high-confidence match, well above the level two unrelated players would reach by coincidence. Lower-scoring comparisons are recorded but never acted on, which keeps siblings on identical machines from banning each other.
When it does act, the ban’s details record the confidence score and the ban ID of the original account, so you can review the decision yourself on the Bans page.
The persistent marker
There’s a second, simpler signal. On first join, Asphyxia stores a small random value in the client’s local game storage. It carries no information — it’s just a unique tag.
If a player turns up whose tag was last seen on an account that’s now banned, that’s a strong indication the two are the same person, and they’re banned as well.
A cheater can clear it. Many don’t, and it’s cheap to check.
Reviewing profiles
Every stored profile is visible on the dashboard’s Fingerprints page, where you can search by license and see which are flagged as belonging to a banned account.
What you’ll see
[Asphyxia.] › ⚠ warn Possible ban evasion — this player's hardware is a 96.4%
match for banned license abc123… (their license: def456…)
[Asphyxia.] › ⚠ warn Possible ban evasion — this player's machine was
previously used by banned license abc123…If it gets it wrong
Two players genuinely sharing one computer — siblings, a LAN centre, a shared household PC — can trip this if one of them gets banned.
The fix is to lift the ban on the account that was wrongly caught from the
Bans page, or with asphyxia unban <banId>. The original ban
stays in place; only the new one is removed.