Mitigation of application-level distributed denial-of-service attacks

An authenticating device, comprising:

• a network communication subsystem;
• and
• a processor configured to enable:
• receiving a pre-authentication request comprising at least a reference for a first group shared secret, the first group shared secret being shared among a plurality of devices comprising a first device with which said pre-authentication request is associated;
• verifying the received pre-authentication request using said first group shared secret;
• receiving an authentication request;
• and
• if the authentication request is determined to have been received from said first device with which the verified pre-authentication request is associated, authenticating the first device in response to the authentication request.

A computer program product comprising a non-transitory computer readable medium bearing program code which, when executed by a processor, causes a computing device to carry out the method of:

• receiving, at an authenticating device, a pre-authentication request comprising at least a reference for a first group shared secret, the first group shared secret being shared among a plurality of devices comprising a first device with which said pre-authentication request is associated;
• verifying, at the authenticating device, the received pre-authentication request using said first group shared secret;
• receiving an authentication request;
• and
• if the authentication request is determined to have been received from said first device with which the verified pre-authentication request is associated, authenticating the first device in response to the authentication request.