---
title: "Fingerprinting"
description: "How Asphyxia recognises a banned player who came back on a fresh account."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.asphyxia.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Fingerprinting

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](/website/bans).

## 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](/website/fingerprints), where you can search by license and
see which are flagged as belonging to a banned account.

> **Note**
>
> The characteristics Asphyxia stores are the same ones any website can read from
> a browser. No file scanning, no process listing, no personal data.

## What you'll see

```text
[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](/website/bans), or with `asphyxia unban <banId>`. The original ban
stays in place; only the new one is removed.

Source: https://docs.asphyxia.dev/anticheat/fingerprinting/index.mdx