A newly-proposed relay protocol could reduce the “transaction bandwidth” used up by bitcoin nodes by up to 75%.
Called Erlay, the proposed protocol alters the way transactions are relayed so that they use significantly less bandwidth, an important resource for the nodes that make up the network. The authors include The University of British Columbia researcher Gleb Naumenko as well as two bitcoin development heavy-weights: Greg Maxwell and Pieter Wuille.
The way bitcoin works is that nodes across the world tie together to form a network. Under the hood, once a transaction is broadcast, it ripples through this vast network of hardware.
Erlay changes up how the announcement of these transactions is performed. As Naumenko described in a bitcoin dev email announcing the new proposal:
“The main idea is that instead of announcing every transaction to every peer, announcements are only sent directly over a small number of connections (only 8 outgoing ones). Further relay is achieved by periodically running a set reconciliation protocol over every connection between the sets of withheld announcements in both directions.”
The results, according to Naumenko: “We save half of the bandwidth a node consumes, allow increasing connectivity almost for free, and, as a side effect, better withstand timing attacks. If outbound peer count were increased to 32, Erlay saves around 75% overall bandwidth compared to the current protocol.”
One important result of this new protocol, the researchers argue, is that by reducing how much bandwidth this process takes, nodes can increase the number of connections they hold with other nodes.
As low-level and technical as it sounds, it’s important research, particularly as it relates to the security of the network itself.