BA-00P · LESSON 05

Back up and recover

KEY DEFINITIONS

Terms used in this lesson

Descriptor: A machine-readable description of the scripts, keys, and derivation paths a Bitcoin wallet watches or can spend.

Protect seed words, passphrase, wallet policy, and derivation information, then test recovery without exposing live secrets.

35 min Difficulty 1/5 Not started

VISUAL MODEL

See the whole mechanism before going step by step

Use the diagrams to orient yourself. Then the guided explanation below teaches every part in depth.

4 explanatory views

CONCEPT-SPECIFIC MAP · wallet recoveryRecovery reproduces a wallet only when every input matchesSelect any state to inspect its exact role.

RELATIONSHIP MAPOrdered mechanism flow

01
WORDSPublished test mnemonic
Only harmless test material belongs in this exercise. Real recovery words must never enter a website.
02
PASSPHRASEEmpty
A different passphrase creates a completely different seed without an error message.
03
NETWORKMainnet
Network version and human-readable prefix change address encoding.
04
POLICYBIP84 native SegWit
Derivation path and output type are required to find the intended branch.
05
RESULTbc1q... expected fixture
A correct recovery is verified against a previously recorded address, not by sending funds first.

Rule shown: Mnemonic, optional passphrase, network, derivation path, and script policy jointly determine which addresses are recovered.

STAGE 1 OF 5WORDS: Published test mnemonic

Only harmless test material belongs in this exercise. Real recovery words must never enter a website.

Governing relationship: Mnemonic, optional passphrase, network, derivation path, and script policy jointly determine which addresses are recovered. Complete path: 1. WORDS, Published test mnemonic. Only harmless test material belongs in this exercise. Real recovery words must never enter a website. 2. PASSPHRASE, Empty. A different passphrase creates a completely different seed without an error message. 3. NETWORK, Mainnet. Network version and human-readable prefix change address encoding. 4. POLICY, BIP84 native SegWit. Derivation path and output type are required to find the intended branch. 5. RESULT, bc1q... expected fixture. A correct recovery is verified against a previously recorded address, not by sending funds first.

1. State transitionWhat exists, what changes, and what results

BEFORE

A test wallet uses 12 words plus an optional passphrase and receives 20,000 sats.

MECHANISM

Record which secrets, public descriptors, passphrases, devices, people, and software versions are needed. Do not assume seed words describe every wallet policy.

AFTER

Treat recovery as a tested procedure with several possible dependencies, not as possession of a word list alone.

Text equivalent: Starting from A test wallet uses 12 words plus an optional passphrase and receives 20,000 sats. The mechanism begins when Record which secrets, public descriptors, passphrases, devices, people, and software versions are needed. Do not assume seed words describe every wallet policy. The resulting lesson is Treat recovery as a tested procedure with several possible dependencies, not as possession of a word list alone.

2. Mechanism pathSelect a stage to inspect its job

STAGE 1 OF 5

List every recovery dependency

Record which secrets, public descriptors, passphrases, devices, people, and software versions are needed. Do not assume seed words describe every wallet policy.

Complete path: 1. List every recovery dependency: Record which secrets, public descriptors, passphrases, devices, people, and software versions are needed. Do not assume seed words describe every wallet policy. 2. Record secrets offline: Write or stamp recovery material away from cameras, cloud notes, email, password managers not chosen for this threat model, and anyone offering support. 3. Separate correlated risks: Avoid storing device and only backup together. For multisignature, separate locations and vendors can prevent one fire, theft, or defect from destroying the quorum. 4. Test recovery: Use a spare or wiped device with a small test wallet, verify expected addresses, then make a controlled spend. A checksum alone is not a recovery test. 5. Plan inheritance and migration: Document how an authorized person can identify the wallet and recovery procedure without giving an attacker an easy single package.

3. Rule and failure boundaryWhat accepts the result and where it can stop

ACCEPTED PATH

Recovery succeeds only when every secret and wallet-policy input recreates expected addresses and can authorize a verified test spend.

CHANGED CONDITION

A missing passphrase does not report an error. It creates a different wallet, so plausible-looking software can hide an incomplete backup until funds are needed.

Important distinction: If the seed words are correct, every Bitcoin wallet must recover automatically. Passphrases, derivation paths, descriptors, multisignature policies, and wallet-specific metadata can also be required.

Text equivalent: The accepted path is enforced by Recovery succeeds only when every secret and wallet-policy input recreates expected addresses and can authorize a verified test spend. If the required condition changes, A missing passphrase does not report an error. It creates a different wallet, so plausible-looking software can hide an incomplete backup until funds are needed.

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Learn the idea

A backup is useful only if it recreates the wallet that can spend. Depending on the wallet, that may require seed words, an optional passphrase, derivation information, output descriptors, multisignature keys, quorum rules, and the correct recovery software. Recovery must be tested without exposing real secrets.

GUIDED EXPLANATION1/5 ideas inspected

List every recovery dependency

Record which secrets, public descriptors, passphrases, devices, people, and software versions are needed. Do not assume seed words describe every wallet policy.

The worked example follows the explanation

Inspect every idea above to open it.

Important distinction“If the seed words are correct, every Bitcoin wallet must recover automatically.”

Passphrases, derivation paths, descriptors, multisignature policies, and wallet-specific metadata can also be required.

FINISH LEARNING FIRST

The questions unlock after every required learning activity

Inspect every guided idea, open the worked example, rebuild its mechanism, and complete the deterministic lesson tool. Your progress is saved automatically.