Bither · BTC

Recover a Bither wallet.

Bither is a lightweight Bitcoin wallet for desktop and mobile, with password-encrypted keys.

Why people get locked out

For a forgotten Bither password when you still have the wallet.

Can we recover it?

Yes. Bither is one of the formats that reduces to a check-only extract, so the fleet can test passwords against it safely — finding the password never exposes a key that holds funds. GPU-friendly. You pay 15% only if we recover it, and nothing if we don't.

Under the hood

The Bither extract, in detail.

Exactly what the fleet receives for this format — and why finding the password still can't move the funds.

Anatomy of the extract

What leaves your machine — and what never does

For a Bither wallet, this is the entire check-only extract the fleet receives. It can test a password, but it can never be turned back into a key that spends.

GPU $bither$
in the extract
  • the last half of the encrypted private key
  • 16 bytes of encrypted padding
stays on your device
  • the first half of the private key — never sent
  • your addresses and balances
how a guess is checked

The padding has predictable structure that a correct password reproduces. Half a private key cannot be reassembled into a spendable key.

verifier predictable padding
example extract
illustrative · synthetic
$bither$<half-privkey-hex>$<padding-hex>

Illustrative and synthetic — placeholder bytes.

on the wire

Half an encrypted private key plus 16 bytes of padding — never a whole key.

password math (KDF)
Password-derived key + AES

The password unlocks an AES-encrypted private key; only a fragment of it is used for verification.

how a guess is recognized
predictable padding

The padding has predictable structure that a correct password reproduces. Half a private key cannot be reassembled into a spendable key.

extract format
$bither$

An open, published format. The agent checks every job matches it before running — so a real wallet can't be disguised as an extract.

See the full security model, or how a recovery works end to end.