MultiBit Classic · BTC

Recover a MultiBit Classic wallet.

MultiBit Classic was the original MultiBit desktop wallet, storing AES-encrypted private-key exports.

Why people get locked out

For a forgotten MultiBit Classic password on an old key-export file.

Can we recover it?

Yes. MultiBit Classic 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 MultiBit Classic 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 MultiBit Classic 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 $multibit$
in the extract
  • the 8-byte OpenSSL salt
  • the first 16-byte ciphertext block
stays on your device
  • the rest of the encrypted private-key export — never sent
  • your addresses and balances
how a guess is checked

A correct password decrypts the first block to valid Base58 private-key text; nothing spendable is reconstructed from the fragment.

verifier valid Base58 key text
example extract
illustrative · synthetic
$multibit$<salt-hex>$<first-block-hex>

Illustrative and synthetic — placeholder bytes.

on the wire

The OpenSSL "Salted__" salt plus one ciphertext block — roughly 24 bytes.

password math (KDF)
OpenSSL EVP_BytesToKey + AES-256-CBC

MultiBit Classic uses OpenSSL's salted format — an MD5-based key derivation over the password and an 8-byte salt, then AES-256-CBC.

how a guess is recognized
valid Base58 key text

A correct password decrypts the first block to valid Base58 private-key text; nothing spendable is reconstructed from the fragment.

extract format
$multibit$

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.