DP 9.04 - Drive based encryption

Hi Team, 

When we enable drive based encryption in data protector 9.04 , the keys get generated when the backup runs (example day1 backup) .  we export the keys to safe location after all backup finishes.

when the next backup schedule (day2 backup) finishes , we export the keys again & save it to safe location.

so , during recovery at DR site , does it require both the keys (Day1 & Day2) to recover the data or the day2 keys only ?