For some reason I cannot access my old Multibit wallet. Now, when I examined the key file of this wallet, the key seems to be shorter compared to test wallets I have created. Can someone explain why the keys are of different length? Could it be that my old wallet has corrupted somehow and the password won't work for that reason?

For example, the locked wallet (wallet-20131111111111.key):

U2FsdGVkX1/RjOlwly6MiJby6ktcNLbMXQJYxncBG6aO2FZc/SE1kVBloeSneQVGckML7MLjTRzU
LQ7vZiTmSfqSTDuuEtpq1P7NILeoBhmwhsT8s6ytXghRt+idDfUM

New wallets I create (wallet-20171111111111.key):

U2FsdGVkX18QDYZux0T+D0hq0MG1FVnlblmXj6oHsCwZJiH55MPG6mfTcHxyr1o6t0UQQ0P7vVA3
awrIjmYXJbmNOCjYlDxsru9JD4sxz6GPhbQxjh4n82/i3F1pWslVdy2/K1B+Q+uEyj0JmwPiwctl
wOUe79ROSG4XvJcHODJuU/Inb29vbdJPNeZCtUyGj/YN91EOpGSP98Rta4UUEEwYTDsHuBQ12AEx
5j4zsy8=