The robust distributed ledger model for a multidimensional blockchain security analysis

The paper considers the problem of constructing a model of the robust distributed ledger for security proof of a multidimensional blockchain. Several requirements for the model are imposed, among which most important are compatibility with existing models and presence of functionalities for external transactions. The authors present an approach to extending existing models based on the analysis of these solutions, their advantages and disadvantages. The model construction is based on universal composability framework. Two models are proposed: a model of the robust distributed ledger and a model of the search and verification protocol. These are meant to be used in security proofs for scaling and registration in a multidimensional blockchain. The proposed model of the robust distributed ledger is an extension of models used in security proofs for consensus mechanisms: proof of work and proof of stake. It duplicates their functions and additionally maintains external transactions. The model of the search and verification protocol implements ideal functionality used for external transaction verification. The results prove that the proposed model does not damage essential security parameters of the robust distributed ledger in presence of external transactions. The study confirms the compatibility of the proposed models with existing analogues implementing robust distributed ledgers. This fact allows using the universal composability theorem for constructing security proofs of multidimensional blockchain and search and verification protocol. The proposed method of extending existing models for security proofs can be used to create new models with additional functions not implemented for security proof of a multidimensional blockchain.