While “don’t roll your own crypto” is in general good advice — it can be bad too.

Being fixated with reusing other cryptographic schemes — even for novel use cases — can be just as dangerous.

Before using someone else’s cryptographic scheme be sure that its actually intended for your use case.

If there isn’t something already for your use case, don’t be afraid to combine cryptographic primitives in a new way —

you’re doing risky things anyway, and throwing in something designed for completely different uses will just hide the danger.

Either way don’t do anything before spending some time looking for previous art and understanding it.