Zero-knowledge data validation method based on the homomorphic hash function in the distributed decentralized storage platform Stanislav Bogatyrev, Anatoly Bogatyrev, Sergei Liubich, and Fabian Wahle JSC ”NEO Saint Petersburg Competence Center”, St. Petersburg, Russia {info,stanislav,anatoly,sergei,fabian}@nspcc.ru https://nspcc.ru Abstract. The design of the Distributed Decentralized Storage Plat- form (DDSP) requires to develop an efficient data validation method taking into account the network scalability issue, possibility to check data without knowledge of content and privacy protection of users data. DDSP is aimed at ensuring the availability and integrity of data. The aim of this research is to develop a zero-knowledge data validation method for the decentralized storage system for minimizing data transferring to maintain the network scalability and minimizing computational cost on the side of a storage node to maintain a large number of parallel interactions, and on the side of a validating node. The integrity guarantee is achieved due to the proposed data validation method based on the homomorphic hash function which allows to verify the integrity of data on a storage node without transferring real data to a validating party over the network. The computational complexity of validations depends linearly on the size of validated data and is well suited for parallelization. Keywords: Zero-knowledge · Data validation · Zero-knowledge data validation · Homomorphic hash · Distributed · Decentralized · Storage platform · Object storage · Storage. 1 Introduction Nowadays, building an efficient, reliable and scalable decentralized data storage architecture is an actual problem in both corporate and academic communities since decentralization requires new approaches that adapt existing models. In the decentralized storage system, where users no longer physically own the storage of their data, traditional cryptographic primitives for the purpose of data security protection cannot be directly adopted [1]. A group of works [1–4] have been done focusing on attempt to solve a remote data validation task in cloud storage. These methods can be classified as Proof of Data Possession(PDP) and Proof of Retrievability(PoR). The PDP scheme initially has been presented by Ateniese [2, 3]. Related protocols detect a large amount of corruption in outsourced data. However, the