Handle overvoting? #22
Description
Right now, if we're asked to encrypt an overvoted ballot, the resulting proofs will not correctly verify. Resolving this issue requires two things:
- interpreting an overvoted contest down to a blank input
- placing something meaningful into the extended data
The extended data is meant to hold write-in data, original (uninterpreted) votes, and other such things, all encrypted with hashed ElGamal but the spec doesn't provide detailed guidance on this.