Initially, I set Msgpluslive to encrypt all my log files. However, I later found out that if the log file is too big, the decryption process become really slow. Now, how can I remove the passwords from the existing log files? Also, if the key for encryption is smaller, does it mean the encryption and decryption would be faster and log file size would be smaller?

Have a look at About uncrypting logs (i've got password!)

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