Blockchains and Post-Quantum Security

Welcome to The Crypto Compass!

Today, let us discuss the potential impact of quantum computing on blockchain security and how Falcon keys are helping to keep blockchains like Algorand secure for the future.

Quantum computing is rapidly evolving field of computer science that utilizes the properties of quantum mechanics to perform operations on data.

Traditional computers use bits which are either on or off, represented as 1 and 0.

Quantum computers use qubits, which can be on or off, or both at the same time. This makes encryption much easier to break.

You can imagine bits as a light switch, either on or off. And qubits as a dimmer switch, on, off, or anywhere in between.

A little confused? You're just like a qubit.

Now, most modern computers use something called hashing. Hashing involves taking an input, doing some mathematical operations on it, and spitting out an output.

There's one feature that makes hashes super useful, the hashing process cannot be reversed. It is effectively a one-way street and is a great way to obscure data.

You use hashes all the time, for example, when you log into a website, the website doesn't check if your password is right, it checks whether the hash of your password matches.

They do this to prevent someone who may intercept the hash from reverse engineering your password.

SHA-256 is the most common hashing algorithm used into the blockchain space. SHA-256 has 2^256 potential outputs, that's a 10 followed by 77 zeros. There's less atoms in the known universe.

Attempting to find an input which gives us a particular hash would take us a very long time.

With qubits, we can see all the outcomes, and can pick the right answer. A bit like Dr Strange looking at all the timelines.

Finally, Falcon Keys.

As quantum computer are a real possibility, Falcon was submitted as part of a post-quantum cryptography project. It represents an algorithm which aims to maintain secure characteristics in environments where quantum computers are presents.

One of the biggest issues facing they algorithms is their performance. It is easy to make a secure algorithm, but it is difficult to make one which is also fast, as this will impact the performance of the end system.

Thankfully, Falcon does a great job of this. The creation of a 1024-bit key takes 27ms and 29kb of RAM.

That's 4x faster than you blinking. And your smartphone could hold 285,000 of those keys.

Algorand has further improved the Falcon algorithm by adding an option for deterministic (or "derandomized") signing. This plays an important part with other deterministic functions within Algorand.

The nature of cryptography is such that the most current algorithms will come under scrutiny from the industry, which will either help it evolve, or make it redundant.

However, as of writing this post, Falcon still remains effective as a post-quantum solution which is being leveraged by blockchains to protect themselves.

There may come a day where Falcon is no longer fit for purpose, but by that time I imagine there will be newer solutions for us to move to.

Only time will tell.

Thanks for reading! If you enjoyed this edition of Farzan's Crypto Compass, feel free to reply to this email and let me know. I read each piece of feedback and take it on board.