As outlined in the introductory post for the HIVE Quantum Resistance Community, HIVE has, or rather, will have, a quantum resistance problem. A problem that the blockchain needs your brain for to solve. If you know a little about cryptography and cryptographic signatures, or if you are a developer, please go and read the introductory post, join the community and weigh in.
In this post I want to throw in a little idea that could potentially help as part of the solution.
An extra (for now) Active key
While HIVE has multiple keys with a hierarchy of sort between them, and all of these keys will eventually need to be addressed, in this post I want to focus on the Active Key. The Active Key is usually the key you will use for monetary transactions, and as an direct theft is the simplest of all attacks an attacker with access to a powerful quantum computer might deploy, I want to look into this scenario in this post.
As we know ECDSA keys aren't quantum resistant. There are a few signing algorithms that are, including, most importantly, hash-based signatures. If you don't know what hash-based signatures are, and have a few hours to burn, have a look at this video where John Kelsey gives a great introduction on the subject.
I won't go too deep into the technical details, but I'll touch on a few essentials. For one, we should realize that hash based signatures work with the equivalence of a public key that gets exhausted by usage. To illustrate this point, have a look at the QRL block explorer
In this case, the public key gets exausted after signing 64 messages. This means a hash based signing key will need to be replaced or the account will become unusable.
A way to set this up for HIVE could be:
- A user can set his/her hash-based public key once using his/her ECDSA Active key or Owner key.
- A user can update his/her hash-based public key using his/her currently active hash-based private key.
- A user can sign monetary transactions using his/her hash-based public key.
- The signature that exausts the old hash based signatre key can only be used to set a new hash based active key.
Two extra on-chain coins.
So what is the point of having a new key if the old ones are still there? Well, enter two new coins. Let's name them QR-HIVE and QR-HBD.
- A user that earns HIVE/HBD while having set a hasing based signatures active key will earn QR-HIVE/QR-HBD instead.
- On a set date, for example January 1st 2023, HIVE/HBD held by users who have set a hashing based signature set, gets converted to QR-HIVE/QR-HBD holdings instead.
- Transferring QR-HIVE/QR-HBD either using the ECDSA active key or sending it to to a user who hasn't set his/her hash-based signature active key yet converts id to HIVE/HBD
On-chain conversion and market driven valuation
Just as with HBD/HIVE, adding on-chain conversion should be useful. We could hardcore a declining conversion rate. Lets say on January 1st 2023 the conversion rate from $HIVE to $QR-HIVE and from $HBD to $QR-HBD starts out at 1.0, slowly decaying a bit every day to, for example end up at 0.05 on January 1st 2023.
If there is also a trading option, the market could decide on a higher value for the non-QR coins.
Loose ends
The above is a simple and incomplete proposal. How could the owner key fit in? What hash based algorithms should we use? How about recovery? How about all the users who lost their owner key and are locked to @steem as recovery account? How about non-monetary quantum computing attacks? None of these questions are addressed here. This post is meant mostly to get the discussion going, to get the juices flowing. If the above post has you thinking about the subject, please consider joining the HIVE Quantum Resistance Community and posting your own blog posts here on the subject.