Cryptography
Last updated
Last updated
Arrays of bytes (like strings and hashes) in the project are encoded by .
When encoding a hash, use the raw bytes and not the hexadecimal notation.
Note that encoding is not encryption. You can decode a base58 encoded message without the need for any type of key.
Examples
The string hello world is encoded as StV1DL6CwTryKyV.
SHA256 hash e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 is encoded as
GKot5hBsd81kMupNCXHaqbhv3huEbxAFMLnpcX2hniwn
When casting objects to JSON, data is sometimes encoded as base64 instead of base58. Base64 encoded strings are always prefixed with base64:.
In general Live Contracts uses the 256-bit version of SHA-2 for encoding. SHA-2 is one of the most common hashing algorithms which means it's available for almost all platforms and programming languages.
When secure hashes are required, a combination of BLAKE2b and SHA256 is used.
The default method for signing is using ED25519. This is an EdDSA algorithm on curve25519. It is designed to be faster than existing digital signature schemes without sacrificing security.
ED25519 is well-supported across many platforms and languages.
There are many valid (not unique!) signatures for one message when using ED25519. Also, you should not rely on any information before the hash and/or signature are checked.
Bitcoin, Ethereum, and many other blockchains use ECDSA with the secp256k1 curve for signing transactions. Outside of the realm of blockchain, this curve is not commonly used.
The most commonly used and well-supported Elliptic Curve is NIST P-256. This is an ECDSA method using the secp256p1 curve.
There are 3 algorithms involved in asymmetric encryption for ED25519 accounts:
Key exchange: X25519
Encryption: XSalsa20 stream cipher
Authentication: Poly1305 MAC
This is a public key encryption schema, where the public key is used to encrypt data and the private key is used to decrypt data.
X25519 is sometimes referred to as Curve25519.
BLAKE2b is supported by NaCl-compatible libraries like libsodium as . It's widely supported across platforms and languages.
Functions for ED25519 are defined as sign in and .
Functions that use the combination of these algorithms are defined as sealed box in . When using , you can recreate this functionality using the box functionality and a random ephemeral public-private key pair.
Encryption for ECDSA (secp256k1 and secp256r1) accounts is done using , which combines ECDSA with AES.