https://github.com/leanprover/cslib/blob/906574d376632467fd84a2a404efbe58a95fc13c/Cslib/Crypto/Protocols/PerfectSecrecy/Internal/OneTimePad.lean#L22
cslib/Cslib/Crypto/Protocols/PerfectSecrecy/Internal/OneTimePad.lean
Line 22 in 906574d