Aptos launches Encrypted Mempool to protect crypto traders from front-running

In the stock market, a broker who takes a peek at a client's order, buys first and sells back at a markup is breaking the rules. In crypto, it is a fairly regular occurrence.

When someone buys crypto, the order sits in a public waiting line for a few seconds before it goes through. Trading bots watch that line, jump ahead of large orders, and sell back at a higher price. Most buyers never notice, and end up paying a little more.

What Aptos just changed

On Oct. 12, the Aptos blockchain switched on a feature called encrypted mempool. In simple terms, it seals an order before it joins the waiting line.

The user's wallet locks the order details on their own device before sending them. The network puts orders in sequence while hiding them from public viewing, and only unlocks them once that sequence is final.

No single party opens the order early. The key is split among the many operators who run the Aptos network, and most of them would have to cooperate to unlock them.

Since the operators already run the network, users aren't trusting anyone new. Aptos says it's the first major blockchain to build this protection in from the ground up.

The extra step adds about 20 milliseconds, a delay too short to notice. Security firm zkSecurity has reviewed the code.