I'm basically a crypto noob (and not an english native), so please be indulgent :)
I thought about if you could realize an eVoting system with bitcoin.
I see 2 major requirements:
- each citizen can only vote once
- votes musn't be traceable
I imagined the government could give each citizen a private key (with their passport for example) and make the actual voting a multisig procedure, where you need to provide the government provided signature plus your own to sign your vote.
Now for my actual question (thx for your patience so far):
Is there some kind of math magic, that makes sure those 2 requirements are met? In other words: Could you, cryptographically use two private keys to sign a transaction, ensuring that one key was issued by a certain CA (= the government) without being able to trace this to the actual user (keeping the vote anonymous).