Multiparty authenticative mechanisms for network-mediated document-object conferencing and collaborative processing

A cryptography-based authenticative framework to support document conferencing is required to address functional complications of unstructured documents, in particular: (1) multi-party authoring characterised by an evolving transactional document, and (2) multi-party authentication on the completed document. Authoring-phase authentication would be provided by: (1) document-object hash trees and (2) a Rabin signature (M.O. Rabin, 1979), respectively providing structural detail for modifications and optimal computationally-efficient verifiability. The authenticative phase would in turn be supported by the Takaragi-Miyazaki-Takahashi (1998) multi-signature protocol featuring a group-associated key pair, the private portion of which is divided into verifiable partial key shares using Feldman-Pedersen verifiable secret sharing (T.P. Pedersen, 1991). Verifiable partial signature affixation can therefore be executed on a completed transactional document-object, with the final result being a simple third-party verifiable discrete logarithm signature. The featured multi-protocol framework would be operationally robust due to its limited dependance on unconditionally trusted transactional entities, which is required for the one-off generation and distribution of multi-signature key parameters.