Multi party signatures and electronic evidence in criminal proceedings

Citation: Václav Stupka / Pavel Loutocký / Antonín Dufka / Petr Švenda, Multi party signatures and electronic evidence in criminal proceedings, in: Jusletter IT 27. April 2023

This paper is devoted to a legal analysis of the possible use of multiparty threshold cryptographic protocols in the handling of electronic evidence in criminal proceedings. In contrast to standard digital signing, multiparty protocols require participation of more than one party to create resulting electronic signature. In the context of criminal proceedings, such signatures can be used to sign documents or data multilaterally to ensure confidentiality and reliability of the chain of custody, in procedural acts and in the transmission of documents. In this article, we describe the functioning of the technology and the technical limits of its use, analyse the nature of signatures generated by it from the perspective of EU law and the possibilities of using this technology in criminal proceedings, taking into account the specifics, practices and limitations of the Czech legal environment.

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