Posting The Key To Your Front-Door … To Stop A Robbery

Before I start, here’s a bit of crypto. With public key encryption, we create a key pair — a public key and a private key. The two work together, so that I can encrypt with one and then decrypt with other. The main usages of this is are signing a transaction and in key exchange. In transaction signing, I encrypt something related to a message (such as the hash of the message) with my private key, and then everyone can prove it was me that signed it by decrypting with my public key (and which is known to everyone who wants it). In the following diagram we can see the two main usages of public key encryption are on the right hand side:

Well, the world still awaits Satoshi Nakamoto to reveal his/her private key, but another mystery has been cleared up. It related to an alerting system which was built into bitcoin, and was released by Bryan Bishop and Andrew Chow. The alerting system is now long-gone, but the developers wanted to release the keys so that they would not pose a future risk.

The bitcoin alerting system had long been criticised for its security model and in 2016 it was effectively retired after a public email by Greg Maxwell [here]. This included…