The Painting The Races at Longchamp by Edouard Manet, dated 1866

Full-RBF in Bitcoin Core?

The ability for users to alter their transactions while they are still waiting for confirmation has considerably better the UX of using Bitcoin, as it allows users to unstuck transactions that would otherwise have taken weeks to process because of too small fees, or even to “cancel” a transaction they made by mistake. Today’s mechanism for doing so, called Opt-in RBF, relies on the user’s transaction signaling that it can be replaced....

July 12, 2022 · 744726 · 12 min · Fanis Michalakis
Nuns at work painting by a follower of Alessandro Magnasco

No, Proof of Work Is Not Some "Costly Mistake"

The desire to write this article came to me from the recent publication of two papers1 by Pr. Jean-Paul Delahaye, professor emeritus at the University of Lille 1 and researcher at the Centre de recherche en informatique, signal et automatique of Lille (CNRS/Centrale Lille Institut/University of Lille). However, I hesitated for a long time before deciding to do it. Indeed, I had the impression that counter-arguments to those of Pr. Delahaye already existed in profusion, freely accessible for those who would take the trouble to look for them....

March 30, 2022 · 729667 · 22 min · Fanis Michalakis

Onion Routing

This article is the first (out of two) concerning Onion Routing. It is also the first of the Routing Series, where I'll try to cover in depth how routing works in the Lightning Network, and how it could work differently (ever heard this story about an ant jumping on a trampoline?). This article is an introduction to Onion Routing, and offers a "high level" view of how it works. The second article will go deeper into the inner workings of Onion Routing in the Lightning Network....

February 9, 2022 · 14 min · Fanis Michalakis

AOPP: regulators getting cheesy?

A (heated) discussion on a specific piece of regulation and its application has quickly spread through Bitcoin Twitter in the last hours, following a tweet by shaquille o’atmeal (@crypt0e): It's more than just Trezor: — shaquille o'atmeal (@crypt0e) January 27, 2022 I found the topic interesting enough to wrap up my thoughts on the matter in a short article. I hope it will also help the reader quickly get grasp of what is at stake here....

January 28, 2022 · 4 min · Fanis Michalakis

What Are PTLCs

If the Lightning Network is so useful today, it is in great part thanks to the fact that payments can be routed inside the network: if Alice wants to pay Bob, it isn’t necessary that she has a direct channel with him. Instead, she can have a channel with Carol and, if Carol has a channel with Bob, use Carol’s channel to reach Bob. With this mechanism arises a new question: how can such payments, that rely on the benevolence of third parties such as Carol, be achieved in a trustless way?...

January 15, 2022 · 17 min · Fanis Michalakis