I have two files
Content of file A
paybackFile_537214-760887_000_20120801.xml paybackFile_354472-544899_000_20120801.xml paybackFile_62-11033_000_2012080
awk 'FNR==NR{a[$2".gpg"];next}(($5 in a) && ($0~/decrypted/))' filea fileb