algorand anonymity applications attacks bitcoin blockchain book bullet-proofs byzantine chainspace consensus credentials crime cryptocurrencies dag data-science ddos discrete-log e-voting ecdsa ethereum exchanges formal-methods game-theory governance key-management lattices layer2 litecoin mining monero network ouroboros pki post-quantum privacy proof-of-* proof-of-space proof-of-stake proof-of-work provable-security ripple scalability secure-multiparty-computation sidechains signatures simple-verification-payments smart-contracts snarks solidity starks storage survey theory thesis truebit trusted-computing wallet whitepaper zero-knowledge zerocash zerocoin