A wallet is not “an address.” It is software that manages keys, tracks UTXOs, builds transactions, and coordinates signing — often across devices.
Complete Step 1 // Required reading in the study plan above, then continue here.
Step 2 — Core idea: HD tree, watch vs sign, backups
Most catastrophic losses are operational: bad backups, leaked seeds, wrong derivation paths, or watching wallets that cannot spend.
Analogy: An HD wallet is a tree of keys grown from one seed. The seed is the orchard’s master cutting — lose it and the orchard is gone; leak it and thieves can harvest everything.
BIP-32 defines hierarchical deterministic keys. BIP-39 encodes seeds as mnemonics. Account standards (BIP-44/84/86 families) organize receiving and change chains.
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Example (illustrative): m/84'/1'/0'/0/5 # regtest native SegWit receive index 5Production designs often split:
- Watching software scans the chain / indexer
- Signing happens in hardware or a secure enclave
PSBTs move unsigned transactions between these roles safely.
Done when: You can explain why seed-only backup can fail for Taproot/multisig without descriptor records.
Step 3 — Path + backup checklist (lab)
Write one receive path for regtest (label address type). List what you would back up vs never store in plaintext. Optional:
bitcoin-cli -regtest getnewaddress "" "bech32"
bitcoin-cli -regtest getaddressinfo <addr>Common mistakes
- Backing up addresses instead of seed + descriptor/script info
- Gap limit surprises (too many unused addresses, balance “missing”)
- Reusing addresses unnecessarily (privacy) or rotating without backup updates
Done when: Lab evidence (path + checklist + source link) is complete.
Next lesson
Descriptors & Miniscript — make wallet policies explicit and portable.