Verifiable Democracy
Yvo Desmedt, Brian King · 1999
In a k out of n threshold signature scheme the secret key is distributed to n participants, so that any subset B of participants, with |B| ≥ k , can combine their shares to form a signature, while any subset of cardinality ≤ k −1 gain no information about the signature. In democratic organizations the number of users vary temporally while maintaining the relationship k = ⌊ n /2⌋+1. The manner in which a legislature votes is similar to a threshold signature scheme, and the power to sign is similar to possessing shares to sign. The transfer of power to sign is an integral part of democracy. In recent work, redistribution schemes have been developed that allow one to vary the threshold k and the number of users n . However, these solutions require parties to delete their shares, which is often an unrealistic assumption. Here we provide a model for democratic bodies and solve the related problem of assuring an orderly and verifiable transfer of power as the size of the body varies.