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.