The Initial Bulletin Board Posting

1st Batch 2nd Batch Empty forms

Envelopes are:• Opaque• Sealed• Bubbles unfilled• Serial numbered(numbers uniqueper batch)

The Pre-printed Ballots

Candidate list permutations are random and kept hidden

Voter Gets Two Ballots & Folds/Fills

Voter chooses whichto fold & which to fill

Voter Gets Receipt & Casts

Voter copies ballot(through redacting folder)

Ballot carried inredacting folder

Voter deposits ballot in ballot box (still in folder)

Voter takes folded ballot and redacted copy of cast ballot as receipt

Copy

Folded Ballot Challenge

Everyone can see that the envelopes in the chain pointed to by the folded ballot were formed correctly.

Marking First EnvelopesSimple transfer from the ballot box to the bulletin board (checked next)

Marked Envelope Challenge

Voters can check that what’s posted matches receipt

1st Trustee Transfers Marks

1st trustee knows what’s written inside envelopes of the 1st batch and can transfer the mark accordingly

Link not revealed

2nd Trustee Transfers Marks

2nd trustee knows what’s in 2nd batch envelopes and uses it to transfer marks

Public Random Challenge

Coin flip per envelope in the first batch, like a lottery draw

Heads: 1st Envelope OpenedX-Ray View

Transferred mark verified consistent with previously secret content of envelope

Tails: 2nd Envelope OpenedX-Ray View Transfer verified

consistent with content of second envelope