LTE: What could be reason for AS security failure ?

Question

I am seeing failure cause = 7 or 1

Which spec defines reselection failure causes?

Answer 1

The SECURITY MODE FAILURE message is used to indicate an unsuccessful completion of a SECURITY MODE COMMAND. i.e., if the SECURITY MODE COMMAND message fails the integrity protection check, then the UE sends SECURITY MODE FAILURE to the eNodeB.

Upon sending this message, the UE shall continue using the configuration used prior to the reception of the SECURITY MODE COMMAND message, i.e. neither applies integrity protection nor ciphering.

For more details please visit the below link:
http://www.3glteinfo.com/lte-security-architecture/