Why is fingerprint lock considered less secure than pattern lock on Nexus 5X? My Nexus 5X highly recommends to set up pattern lock in addition to fingerprint lock, and the pattern is asked upon every reboot. And my password manager (KP2A) recommends to use fingerprint unlock only to &quot;quick unlock&quot; after a short period of inactivity, but to require full password for the DB after every reboot.
Hence two questions:

Why does Google considers the fingerprint lock as less secure than pattern lock?

Using your fingerprint to unlock your device may be less secure than a strong password, PIN, or pattern.


For my password manager on Android, is it really much safer to re-enter password upon every reboot rather than to use fingerprint lock? How many bits my password should have to be more secure than fingerprint lock?


Please note that I'm asking specifically on fingerprint scanner implementation in 5X, not for a general theory on an average abstract fingerprint scanner solution.
The weakness is actually in the fingerprints themselves and not the way Nexus 5x implements it.

Fingerprints are less secure because they cannot be changed like a password and cannot be revoked if compromised.

Fingerprints are also left everywhere such as, at a glass. They can then be captured and reproduced. Think about this: Android uses a touch screen. The fingerprints are left on the screen after device's usage.

With a fingerprint it's almost good then it is good enough. Because the way it is touched or if you have a cut. Making fingerprints not hashable. Compared to a pin which has to be perfect every time.

They can be taken without permission. Not only from being left behind but also legally without consent. If a password is in your head it must be given, thereby, also leaving your right to privacy and your right to remain silent.

In the United States a person is also protected from testifying against themselves by the 5th amendment. Legally, fingerprints are considered as physical objects because they exist in the physical world. So they are not protected by the 5th amendment.