https://github.com/crei/cslib/blob/c1f2e8ee0d9ac0a955793f665a656958e924779f/Cslib/Crypto/Protocols/PerfectSecrecy/Internal/OneTimePad.lean#L22
cslib/Cslib/Crypto/Protocols/PerfectSecrecy/Internal/OneTimePad.lean
Line 22 in c1f2e8e