KME Systems offers advice for encryption attacks that can permanently damage files with 1024 bit key strength
QUOTE: Backup your files before Cryptolocker infects your computer. Due to the popularity of these ransomware viruses, PC and Mac users should regularly backup their files. Once the malware has infected a computer, there’s no way to restore access to those encrypted files. At that point, the best option would be to have your IT department reformat the computer and restore files from a previously saved backup set. You can also attempt to decrypt your files on your own as an alternative to paying a fine or if you don’t have an IT department.
For Mac Users: Click on the Safari menu and choose “reset Safari.” Make sure all check boxes are selected or hold the Shift key down while re-launching Safari. This prevents Safari from reopening windows and tabs from your previous session. In addition, disable the reopening feature across OS X from the “General” setting in “System Preferences.”
For PC Users: Turn your computer off, and restart in “safe mode.” Then, follow Windows instructions to do a “System Restore.” If the above tips for decrypting your files fail to work, and you or your IT department is unable to solve the problem, many sources have reported that paying the fine actually does result in a decryption key. However, paying the fee does result in funding for cybercriminals, which helps them create even more viruses.