|0||The purpose is data encryption, corresponds to ALG_CLASS_DATA_ENCRYPT in WinAPI. Typical examples are RC2 and RC4.|
|1||The purpose is creating an irreversible hash of some data, corresponds to ALG_CLASS_HASH in WinAPI. Typical examples are MD2, MD5, SHA-1, and MAC.|
|2||The purpose is key exchange, corresponds to ALG_CLASS_KEY_EXCHANGE in WinAPI. A typical example is RSA_KEYX.|
|3||The purpose is creating a signature of some data, corresponds to ALG_CLASS_SIGNATURE in WinAPI. A typical example is RSA_SIGN.|
|4||The purpose is unknown.|
In WinAPI, algorithm category is known as algorithm class.