Question: what is pbkdf2 used for?
Answer: PBKDF2. In cryptography, PBKDF1 and PBKDF2 (Password-Based Key Derivation Function 2) are key derivation functions with a sliding computational cost, used to reduce vulnerabilities to brute force attacks. PBKDF2 is part of RSA Laboratories' Public-Key Cryptography Standards (PKCS) series, specifically PKCS #5 v2.