Split numbers in pairs
14 04 21 17 18 j 09 16 18 04 l 12 19 04 l 16 20 22 j 21 18
Convert numbers to letters using a=0
OEVRSjJQSElMTElQUWjVS
We now have 21 characters which is a bit odd. If you convert from Base64 you get the prefix and a good part of the keyword.
Let’s split things a bit to try to find out what is wrong
OEVRSjJQSElMTElQ
WjVS
We have to dismiss the U for now because we need 16 characters
Convert these from Base64
8EQJ2PHILLIP
Z5R
We know the keyword should be PHILLIPS which explain the U in the original string.
Now we need to brute the first letter and first numbers of the suffix. The winning combination is N8. So the good Base64 string would be
OEVRSjJQSElMTElQU044WjVS
Convert Base64 to Ascii
8EQJ2PHILLIPSN8Z5R
