CRYPTED file extension is used by files created with WinOptimizer, a tool developed by Ashampoo. CRYPTED file stores encrypted version of given file. Encrypted files allow users to restrict access to file without the need of encrypting the whole disk.

CRYPTED file can be opened using WinOptimizer after verifing credential by supplying correect security password created during file encryption process. WinOptimizer is a paid software, and is avaliable in many languages.