From 8c5b2fd291826209a7909de01c096bf1a4e15fd2 Mon Sep 17 00:00:00 2001 From: "David A. Harding" Date: Thu, 9 Feb 2023 18:59:18 -1000 Subject: [PATCH] CH04::privkey formats: add sidebar about format relevancy Most software today doesn't export or import private keys, so add a sidebar noting that this section is mainly for historical reasons. --- ch04.asciidoc | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/ch04.asciidoc b/ch04.asciidoc index 1fef6ee5..d46903b8 100644 --- a/ch04.asciidoc +++ b/ch04.asciidoc @@ -946,6 +946,31 @@ internally in software and rarely shown to users. The WIF is used for import/export of keys between wallets and often used in QR code (barcode) representations of private keys. +.Modern relevancy of private key formats +**** +Early Bitcoin wallet software generated one or more independent private +keys when a new user wallet was initialized. When the initial set of +keys had all been used, the wallet might generate additional private +keys. Individual private keys could be exported or imported. Any time +new private keys were generated or imported, a new backup of the wallet +needed to be created. + +Later Bitcoin wallets began using deterministic wallets where all +private keys are generated from a single seed value. These wallets only +ever need to be backed up once for typical onchain use. However, if a +user exports a single private key from one of these wallets and an +attacker acquires that key plus some non-private data about the wallet, +they can potentially derive any private key in the wallet--allowing the +attacker to steal all of the wallet funds. Additionally, keys cannot be +imported into deterministic wallets. This means almost no modern +wallets support the ability to export or import an individual key. The +information in this section is mainly of interest to anyone needing +compatibility with early Bitcoin wallets. + +For more information, see <>. + +**** + [[table_4-2]] .Private key representations (encoding formats) [options="header"]