@ -108,7 +108,7 @@ If you are implementing a bitcoin wallet, it should be built as a hierarchical d
((("wallets", "technology overview", "using bitcoin wallets")))In <<user-stories>> we introduced Gabriel, an enterprising young teenager in Rio de Janeiro, who is running a simple web store that sells bitcoin-branded t-shirts, coffee mugs, and stickers.
Gabriel uses a Trezor bitcoin hardware wallet (<<a_trezor_device>>), to securely manage his bitcoin. The Trezor is a simple USB device with two buttons that stores keys (in the form of an HD wallet) and signs transactions. Trezor wallets implement all the industry standards discussed in this chapter, so Gabriel is not reliant on any proprietary technology or single vendor solution.
((("Trezor bitcoin hardware wallet")))Gabriel uses a Trezor bitcoin hardware wallet (<<a_trezor_device>>), to securely manage his bitcoin. The Trezor is a simple USB device with two buttons that stores keys (in the form of an HD wallet) and signs transactions. Trezor wallets implement all the industry standards discussed in this chapter, so Gabriel is not reliant on any proprietary technology or single vendor solution.
[[a_trezor_device]]
.A Trezor device: a bitcoin HD wallet in hardware
@ -148,11 +148,11 @@ For the first implementation of his web store, Gabriel uses a single bitcoin add
[[mnemonic_code_words]]
==== Mnemonic Code Words (BIP-39)
Mnemonic code words are word sequences that represent (encode) a random number used as a seed to derive a deterministic wallet. The sequence of words is sufficient to re-create the seed and from there re-create the wallet and all the derived keys. A wallet application that implements deterministic wallets with mnemonic words will show the user a sequence of 12 to 24 words when first creating a wallet. That sequence of words is the wallet backup and can be used to recover and re-create all the keys in the same or any compatible wallet application. Mnemonic words make it easier for users to back up wallets because they are easy to read and correctly transcribe, as compared to a random sequence of numbers.
((("wallets", "technology details", "mnemonic code words")))((("mnemonic code words", id="mnemonic05")))((("bitcoin improvement proposals", "Mnemonic Code Words (BIP-39)", id="BIP3905")))Mnemonic code words are word sequences that represent (encode) a random number used as a seed to derive a deterministic wallet. The sequence of words is sufficient to re-create the seed and from there re-create the wallet and all the derived keys. A wallet application that implements deterministic wallets with mnemonic words will show the user a sequence of 12 to 24 words when first creating a wallet. That sequence of words is the wallet backup and can be used to recover and re-create all the keys in the same or any compatible wallet application. Mnemonic words make it easier for users to back up wallets because they are easy to read and correctly transcribe, as compared to a random sequence of numbers.
[TIP]
====
Mnemonic words are often confused with "brainwallets." They are not the same. The primary difference is that a brainwallet consists of words chosen by the user, whereas mnemonic words are created randomly by the wallet and presented to the user. This important difference makes mnemonic words much more secure, because humans are very poor sources of randomness.
((("brainwallets")))Mnemonic words are often confused with "brainwallets." They are not the same. The primary difference is that a brainwallet consists of words chosen by the user, whereas mnemonic words are created randomly by the wallet and presented to the user. This important difference makes mnemonic words much more secure, because humans are very poor sources of randomness.
====
Mnemonic codes are defined in Bitcoin Improvement Proposal 39 (see <<appdxbitcoinimpproposals>>). Note that BIP-39 is one implementation of a mnemonic code standard. Specifically, there is a different standard, with a different set of words, used by the Electrum wallet and predating BIP-39. BIP-39 was proposed by the company behind the Trezor hardware wallet and is incompatible with Electrum's implementation. However, BIP-39 has now achieved broad industry support across dozens of interoperable implementations and should be considered the de-facto industry standard.
@ -298,7 +298,7 @@ There is also a BIP-39 generator implemented in a standalone webpage, which is e
judymcconville@roadrunner.com
7 years ago