Media type: E-Article Title: Crypto Currencies and Block Chain System Contributor: Oprișan, Oana; Dumitrache Șerbănescu, Ana-Maria; Spînu, Remus imprint: Universitatea Ovidius din Constanta, 2022 Published in: Ovidius University Annals. Economic Sciences Series Language: Not determined DOI: 10.61801/ouaess.2022.1.126 ISSN: 2393-3119; 2393-3127 Origination: Footnote: