Practical solutions to save bitcoins applied to an identity system proposal

In a recent work by Augot et al. (2017), a scheme is proposed to build an identity system on top of the Bitcoin network. However, this proposal incurs very high costs since Bitcoin transactions require heavy fees. The current work introduces modifications to their scheme to make it more cost efficient while preserving its potential. Namely, we build on features of Bitcoin’s scripting language, which allows swapping coins between two compatible blockchains, and also on off-chain transactions.