Side channels? Is best out of 2 sufficient or is best out of 3 necessary?

From https://news.ycombinator.com/context?id=39938759 re: s2n-tls:

> [ FizzBee, Nagini, Deal-solver, Dafny; icontract, pycontracts, Hoare logic, DbC Design-by-Contract, invariants, parallelism and concurrency and locks, io latency, pass by reference in distributed systems, "FaCT: A DSL for Timing-Sensitive Computation" and side channels [in hw and software] https://news.ycombinator.com/item?id=38527663 ]

There are so many things to consider;

/? awesome-safety https://westurner.github.io/hnlog/#search:awesome-safety :

awesome-safety-critical: https://awesome-safety-critical.readthedocs.io/en/latest/

Hazard (logic) https://en.wikipedia.org/wiki/Hazard_(logic)

Hazard (computer architecture); out-of-order execution and delays: https://en.wikipedia.org/wiki/Hazard_(computer_architecture)

Soft error: https://en.wikipedia.org/wiki/Soft_error

SEU: Single-Event Upset: https://en.wikipedia.org/wiki/Single-event_upset

And then cosmic ray and particle physics