Recovery by two sets of 32 bit keystream authentication
UID
Tag challenge #1 (aka nt)
nt
Reader challenge #1 (aka nr_0)
nr_0
Reader response #1 (aka ar_0)
ar_0
Tag challenge #2 (aka nt1)
nt1
Reader challenge #2 (aka nr_1)
nr_1
Reader response #2 (aka ar_1)
ar_1
Recovery by two sets of 32 bit keystream authentication