bigchaindb/docs/source/cryptography.md

Cryptography

The section documents the cryptographic algorithms and Python implementations that we use.

The implementations that we have chosen for now are just for fast prototyping. Some of them are pure Python implementations which may be slow. As future work, we should look at other alternatives.

Hashes

For hashing we are using the sha3-256 algorithm and pysha3 as the Python implementation. We store the hex encoded hash in the database. For example:

import hashlib
# monkey patch hashlib with sha3 functions
import sha3

data = "message"
tx_hash = hashlib.sha3_256(data).hexdigest()

Signature algorithm and keys

The signature algorithm used by BigchainDB is ED25519 using the python ed25519 module, overloaded by the cryptoconditions library.

The private key is the base58 encoded hexadecimal representation of private number. The public key is the base58 encoded hexadecimal representation of the compressed public numbers.