Good enforcement is impossible without subjecting anybody trading stocks and everybody they know to a completely unprecedented level of surveillance. This would have to go far beyond the wildest Snowden revelations.
Perhaps not completely impossible in theory, but absolutely infeasible in practice. Building such a system would also be likely to result in far greater chilling effects on the markets than insider trading ever could.
Why? Just look for a pattern of abnormal returns. (Hint: the SEC does this.) It's much easier to check for insider information after the fact than it is to profitably trade on it.
Does it work? (Hint: no)
> It's much easier to check for insider information after the fact than it is to profitably trade on it.
This is only true for the least sophisticated insider traders.
Every trade has to be disclosed. There isn't a block-chain involved, but their is an e-paper trail. We are on a technology forum in a time where ten people could probably put together a domain model that tracks potential conflicts based on peoples trades, google contacts, and linkedin profile. And any person who traded on insider information in the past probably leaves a pattern.