4 ms·
It's some kind of EC/DSA scheme, isn't it? Then from the private key you can indeed get the public key.
by red_admiral 2y ago
It's some kind of EC/DSA scheme, isn't it? Then from the private key you can indeed get the public key.
- mistrial9 2y agoIs this true? from an ECDSA private key you could derive many possible public keys? asking for a friend
- aeonik 2y agoI looked it up. 1. SHA-256: Used twice (double SHA-256) for block hashing and once in address generation. 2. RIPEMD-160: Used once in address generation (after SHA-256). 3. ECDSA: Used once for transaction signing and verification. 4. Base58Check: Used once for address encoding (includes a checksum generated using SHA-256).
- treyd 2y agoFor simple key derivation no, just the one pubkey. However most crypto wallets use a "hierarchical derivation" [1] scheme. [1] https://www.ledger.com/academy/crypto/what-are-hierarchical-deterministic-hd-wallets https://www.ledger.com/academy/crypto/what-are-hierarchical-...
- red_admiral 2y agoIf you have a normal ECDSA private key, you get only one public key. However, there are ways to get a 1-to-many scheme, and similar ideas are used in U2F (yubikey or similar) systems. The basic idea is you pick one private key that's a sequence of 256 bits or so, call this k. When you need a keypair, you compute H(k, tag) to get another bitstring, then turn that into an ECDSA private key (minding the bear traps here) and that then has a single public key. For example in U2F, the key derivation is H(k, domain, ...) where k is the secret baked into the USB token, domain is the domain you're logging in to (this is the part that protects against phishing, among other things) and further protocol-specific information.