Signature aliasing
Beginner
When a broken chip’s fingerprint happens to match a good chip’s, so the flaw slips by.
Novice
The chance that a faulty chip’s squeezed-down result happens to equal the good result, hiding the fault. For a -bit MISR it is about 1 in .
Expert
Negligible for practical sizes (32 bits or more), but never zero. Simpler compactors such as parity or counting 1s alias far more often.