18 lines
544 B
Python
18 lines
544 B
Python
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from merkle_tree import blake
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# Get the set of powers of R, until but not including when the powers
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# loop back to 1
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def get_power_cycle(r, modulus):
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o = [1, r]
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while o[-1] != 1:
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o.append((o[-1] * r) % modulus)
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return o[:-1]
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# Extract pseudorandom indices from entropy
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def get_pseudorandom_indices(seed, modulus, count):
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assert modulus < 2**24
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data = seed
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while len(data) < 4 * count:
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data += blake(data[-32:])
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return [int.from_bytes(data[i: i+4], 'big') % modulus for i in range(0, count * 4, 4)]
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