Does a nuclear weapon (B-61) equipped F-35 have the same nuclear confirmation failsafes as other nuclear device delivery aircraft?
Traditionally many single seater aircraft have had nuclear weapons capabilities. 

To name a few:


A-4 
F-104 
F-105 
F-84
F-16
A-7 (I think)
F-102
F-106
F-88
F-101


This list isn't exhaustive. The release of the weapon will typically be authorised before takeoff, the pilot then having the electronics on board to enter the final arming codes that will bring the weapon life. I'm not in the know about the exact procedures here, but my guess is someone on the ground acts as the first of the two keys before the flight starts, and the pilot entering his codes into the arming console during the flight acts as the second. This is far more reliable and less error prone than having the code transmitted to the weapon during flight over a radio link which may be jammed, detected, or simply not work in a nuclear war scenario.