, Some benchmarks from academic references The reference paper on Bitcoin is the paper of Nakamoto Presentation of some altcoins with their protocols are developed in Bitfury Group (2015), see also ECB (2015) and Guégan (2017b) Ethereum has been introduced by Buterin (2015), see also Woods (2016) and some comments in Guégan For information on the rules considered in US and Europe concerning Bitcoin we refer to Guégan and Soritopoulou (2017), and a lot of references therein and for an introduction to the risks on ICO to Guégan, all the developments are still in their infancy. For now concerning mining we refer to Pappalardo et al. (2017b), costs relative to the network Bitcoin are discussed in Aste, 2008.

T. Aste, The fair cost of Bitcoin proof of work, WP, UCL, London Bitfury group (2015) Proof of Stake versus proof of work, 2017.

V. Buterin, A next generation smart contract and decentralized application platform, 2015.

C. European and . Bank, Virtual Currency Schemes : A further analysis, 2015.

D. Guégan, Blockchain publique et contrats intelligents (Smart Contrats) :) Les possibilités ouvertes par Ethéreum? et ses limites, 2017.

D. Guégan, Les ICO une nouvelle façon de lever des fonds sans contrainte ?, Revue banque, 2018.

D. Guégan and A. Soritopoulou, Bitcoin and the challenge for regulation, Capital Markets law Journal, 2017.

S. Nakamoto, A Peer-to-Peer electronic Cash System, https :// bitcoin.org/bitcoin The Bitcoin pees network, 2008.

G. Pappalardo, T. Di-matteo, G. Caldarelli, and T. Aste, Blockchain inefficiency in the Bitcoin Peers network, 2017.

G. Wood, Ethereum : a secure decentralized generalized transaction ledger, yellow paper, 2016.