>Fingerprints or the iris sensor is an improvement for them because they are quick and easy to use.
I'm not sure about it being an improvement, human laziness always finds a way to make something less secure. Like buying "fingerprint stickers" because too lazy to pull off a glove when wanting to unlock the phone [0].
The CCC always does interesting stuff like this, a couple of years they reproduced a politicians fingerprint just using photos of her hands [1].
This kind of stuff turns biometrics from something "you are" (your fingerprint, your iris) to something "you have" (a fingerprint on a glove, a picture of an iris) making biometrics often very trivial to bypass.
Fingerprints are even worse. They are all over your phone. So if someone steals it the key is already included.
Fingerprints are something you leave all over the place right now and with the increased camera placement and tracking done everywhere pictures of your iris wont be much better for long. So both are not something you are or have, they are something everyone you ever passed on the street has access to.
I'm not sure about it being an improvement, human laziness always finds a way to make something less secure. Like buying "fingerprint stickers" because too lazy to pull off a glove when wanting to unlock the phone [0].
The CCC always does interesting stuff like this, a couple of years they reproduced a politicians fingerprint just using photos of her hands [1].
This kind of stuff turns biometrics from something "you are" (your fingerprint, your iris) to something "you have" (a fingerprint on a glove, a picture of an iris) making biometrics often very trivial to bypass.
[0] http://gizmodo.com/these-fake-fingerprint-stickers-let-you-a...
[1] https://arstechnica.com/security/2014/12/politicians-fingerp...