This is because, I assume, the AWS policy execution has a number of “operators” and “operands”, and in this case, you’re using the StringLike operand on the account ID string.

Anyway, this discussion is a bit amusing to me, since Devops people are discovering side channels[1] now, although other types of side channels such as speculative execution side channels on CPUs (Meltdown, Spectre) already made waves at the time of discovery, and before that we had power analysis[2] and Magnetostriction detection, and constant time cryptography (this one is a field of its own, so I omit references.)

[1] https://en.m.wikipedia.org/wiki/Side-channel_attack [2] https://en.m.wikipedia.org/wiki/Power_analysis