To protect your sensitive data, F-Secure KEY uses the Advanced Encryption Standard with a key size of 256 bits. This algorithm works in the CCM mode for encryption; CCM is an acronym for a longer abbreviation, namely CTR mode with CBC-MAC. CTR stands for Counter, CBC stands for Cipher Block Chaining, and MAC stands for Message Authentication Code. Nowadays, AES is the recommended standard for modern data encryption.
The master encryption key is derived from your master password using the Password-Based Key Derivation Function 2 (PBKDF2) algorithm specified in the Public-Key Cryptography Standards (PKCS) #5; in the PBKDF2 algorithm, we use the Hash-based Message Authentication Code (HMAC) SHA256, random salts and 20,000 of iterations. This makes it much more difficult to recover the keys through Brute-force or Dictionary attacks, even for weaker passwords.