who has already been given a pseudonym; therefore, a list of participants could be collected, but they can’t be linked to their real-world identities; it’s not clear how to bootstrap the initial set of trusted users to get them to blindly sign each other’s certificates.

Self-sovereign identity solutions usually rely on identities from social networks, but their Sybil-resistance is very questionable because almost half of their accounts could be fake[@facebookNYT]: in spite of this, SybilQuorum[@sybilQuorum; @sybilQuorumArxiv] proposes the use of social network analysis techniques to improve their Sybil-resistance; other research projects consider privacy-preserving cryptographic credentials from federated online identities[@2014arXiv1406.4053M].

Regarding the game-theoretic aspects, most papers focus on attacking only one cryptocurrency (e.g., selfish mining[@DBLP:journals/corr/EyalS13], miner’s dilemma[@DBLP:journals/corr/Eyal14], fork after withholding[@DBLP:journals/corr/abs-1708-09790]). For a recent survey of these topics, see[@sokGameTheoryCryptocurrencies]. Exceptionally, “*Game of Coins*”[@DBLP:journals/corr/abs-1805-08979] considers the competition between multiple cryptocurrencies: a manipulative miner alters coin rewards in order to move miners to other cryptocurrencies of his own interest (with a fixed cost and a finite number of steps). However, in this paper, it’s the cryptocurrency issuer who changes the rewards in order to attract miners from other cryptocurrencies by producing the most efficient cryptocurrency to mine.

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