Random

Randomness in an Intelligent Contract should use seeded random values because getting random data in the deterministic part may be difficult. Delegating randomness to a non-deterministic block can cause the contract to either never agree on that block or to trust the leader.

Seed acquisition methods

1. Use some field of message
2. Use current time (transaction time)
3. Use stdin, as shown below

def get_random_seed() -> bytes:
    import os
    import hashlib
    f = os.fdopen(0, 'rb', buffering=0, closefd=False)
    f.seek(0)
    hash_obj = hashlib.sha256()
    while True:
        chunk = f.read(8192)
        if not chunk:
            return hash_obj.digest()
        hash_obj.update(chunk)