Broadcast Authentication With Preferred Verifiers

We introduce a novel cryptographic paradigm of broadcast authentication with “preferred” verifiers (BAP). With BAP, the message source explicitly targets a set of one or more verifiers. For an attacker, forging authentication data of a source, for purposes of fooling preferred verifiers may be substantially more difficult than fooling other (non-preferred) verifiers. We investigate broadcast authentication (BA) with hashed random pre-loaded subsets (HARPS), which caters for such a distinction. HARPS, provides for efficient broadcast authentication, with and without preferred verifiers. We argue that BA using HARPS has some very desirable features that make it well suited for securing ad hoc routing protocols. We also briefly discuss some applications of the novel paradigm of BAP in the context of ad hoc routing protocols.