Blockchain is one of the most interesting emerging technologies nowadays, with applications ranging from cryptocurrencies to smart contracts. This paper presents a review of the cryptographic tools necessary to understand the fundamentals of this technology and the foundations of its security. Among other elements, hash functions, digital signatures, elliptic curves, and Merkle trees are reviewed in the scope of their usage as building blocks of this technology. Keywords: asymmetric cryptography; bitcoin; blockchain; digital signature; elliptic curves; hash function, merkle tree.
Funding
This work was supported in part by the Ministerio de Economía, Industria y Competitividad (MINECO), in part by the Agencia Estatal de Investigación (AEI), in part by the Fondo Europeo de Desarrollo Regional (FEDER, UE) under Project COPCIS, Grant TIN2017-84844-C2-1-R, and in part by the Comunidad de Madrid (Spain) under Project reference P2018/TCS-4566-CM (CYNAMON), also cofunded by European Union FEDER funds. Víctor Gayoso Martínez would like to thank CSIC Project CASP2/201850E114 for its support.
