The JWE key management algorithms based on PBKDF2 require a JOSE Header
Parameter called p2c (PBES2 Count). This parameter dictates the number of
PBKDF2 iterations needed to derive a CEK wrapping key. Its primary purpose
is to intentionally slow down the key derivation function, making password
brute-force and dictionary attacks more resource- intensive.

Therefore, if an attacker sets the p2c parameter in JWE to a very large
number, it can cause a lot of computational consumption, resulting in a DOS
attack