Secure Communication via Shared Knowledge and a Salted Hash in Ad-Hoc Environments

Decentralized, message-based communication networks commonly require mechanisms for message confidentiality and integrity. While these needs are traditionally provided through methods of channel encryption and signing, such mechanisms are often difficult or impossible to implement in the ad-hoc, decentralized environments seen in sensor networks, collaborative intrusion detection systems, or other similar peer-to-peer networks. Using the concepts from one-way hashing and language-derived relevance theory, we propose five novel contributions relevant to ad-hoc communications and security: one-way cryptographic hashing as a mechanism for securely communicating in an environment where preexisting shared knowledge exists, hashed shared knowledge messages as a basis for secure formation of self-selecting subgroups and trust building, adding salt to the shared knowledge hashes to remove the static nature of common messages and defend against precomputed table attacks, integration of variable complexity hash functions to dynamically adjust hash complexity relative to message complexity, and a message integrity element based on the secrecy of the original shared knowledge within a hashed message. Although our proposed mechanisms are likely implemented without difficulty from a network and encryption standpoint, they do require significant integration and awareness within the applications relying on them. The method also assumes a static value from a large existing set of shared knowledge, which does not always exist.