These values specify an authentication level, which indicates the amount of authentication provided to help protect the integrity of the data. Each level includes the protection provided by the previous levels.
Constant/value
Description
RPC_C_AUTHN_LEVEL_DEFAULT
0
Tells DCOM to choose the authentication level using its normal security blanket negotiation algorithm. For more information, see Security Blanket Negotiation.
RPC_C_AUTHN_LEVEL_NONE
1
Performs no authentication.
RPC_C_AUTHN_LEVEL_CONNECT
2
Authenticates the credentials of the client only when the client establishes a relationship with the server. Datagram transports always use RPC_AUTHN_LEVEL_PKT instead.
RPC_C_AUTHN_LEVEL_CALL
3
Authenticates only at the beginning of each remote procedure call when the server receives the request. Datagram transports use RPC_C_AUTHN_LEVEL_PKT instead.
RPC_C_AUTHN_LEVEL_PKT
4
Authenticates that all data received is from the expected client.
RPC_C_AUTHN_LEVEL_PKT_INTEGRITY
5
Authenticates and verifies that none of the data transferred between client and server has been modified.
RPC_C_AUTHN_LEVEL_PKT_PRIVACY
6
Authenticates all previous levels and encrypts the argument value of each remote procedure call.