Authentication in a computer network system

A method for authenticating access to a target host in a computer network based on security credentials issued for a client host by a security authority, the method comprising:

• receiving at the target host from the client host an emergency security credential in association with a request for access,
• detecting an error indication in association with the received emergency credential indicative that the client host is prevented from obtaining a security credential from the remote security authority for use in accessing the target host, and
• in response to said detecting, performing at least one additional security operation in association with processing the request for access based on the emergency security credential.

A method for issuing security credentials by a security credential server for access authentication in a computer network, comprising:

• creating an emergency security credential for use by a client host in accessing a target host when the client host cannot obtain a security credential from the security credential server, wherein the emergency security credential is configured to provide an error state indication, and
• sending the emergency security credential to the client host for storing in a storage of emergency security credentials.

A data processing apparatus for a client host use for authentication in a computer network system based on security credentials issued by a remote security authority, the data processing apparatus comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the client host to:

• detect that the client host is prevented from obtaining security credentials from the remote security authority for use in accessing a target host,
• in response to said detecting, obtain an emergency security credential from a storage of emergency security credentials, and
• send the emergency security credential with an error state indication to the target host.

A data processing apparatus for a target host for use in authentication of clients hosts in a computer network system based on security credentials issued by a remote security authority, the data processing apparatus comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the target host to:

• receive from a client host an emergency security credential in association with a request for access,
• detect an error indication associated with the received emergency credential indicative that the client host is prevented from obtaining a security credential from the remote security authority for use in accessing the target host, and
• in response to said detecting, perform at least one additional security operation in association with processing the request for access based on the emergency security credential.

A data processing apparatus for a security credential authority apparatus for use in issuing security credentials for authentication of clients hosts in a computer network system, the data processing apparatus comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the security credential authority apparatus to:

• create an emergency security credential for use by a client host in accessing a target host when the client host cannot obtain a security credential from the security credential server, wherein the emergency security credential is configured to comprise an error state indication, and
• send the emergency security credential to the client host for storing in a storage of emergency security credentials.

An authentication credential issued by a security authority for use by a client host for accessing a target host in a data communication system, the authentication credential comprising at least one security feature for use in an authentication procedure between the client host and the target hosts, and an indication that the security credential is an emergency security credential used in response to detection of an error situation preventing the client host from obtaining a security credential from the security authority.