John Odum is the Montpelier city clerk and a certified ethical hacker. The term “Q-Day” doesn’t mean much to most people, but it’s a term we may all come to know within the next decade, and it doesn’t hurt to think about it in terms of elections. Q-Day is the hypothetical moment at which a powerful computer can break the public-key cryptography, the encryption system that secures much of today’s digital infrastructure — think the HTTPS in your w…