Q-Day is the day when classical computational cryptography we use today is slated to be obsolete because quantum computers will finally be powerful enough to crack them. It is likely to have a similar effect as the Y2K crisis in that many digital security systems are not ready for all their communications to be easily crackable. The good news is that people can, and are, starting to fix things now. The bad news is that when it happens, the effects will be very immediate and catastrophic. Even that, however, is only half the story.

Konstanitinos Karagiannis provides one of the best, fullest discussion of the upcoming crisis. He gives us a much clearer idea of when quantum computers will be able to break just about all existing cryptography – including all the encryption underlying Bitcoin and other online digital currencies. And it’s much sooner than people were thinking even 2 or 3 years ago. Like fusion power, it was always thought this day was 10-20 years away.

The summary?

NIST says that all systems should have switched to quantum computing safe security algorithms by 2035 – but Konstanitinos says it’s MUCH more likely that we’ll see real quantum cracking happen sometime around 2027 based on the recent rapid developments in quantum computing and algorithms. He points out its likely to start from government backed security agencies or very powerful, well funded organized crime groups.

What does this mean? It means any companies not updated to quantum secure cryptography will have computing systems almost completely vulnerable to customer data theft, take-over, destruction, and ransom attacks. Secure emails and chat communications will be perfectly readable and usable for blackmail or extortion. Secure government and military communications will become vulnerable to infiltration. Infrastructure systems from airline traffic control, public transit, water systems, to power systems become vulnerable to ransom attacks, havoc, and destruction.

It also means bitcoin and all digital currencies based on elliptical encryption/similar algorithms are very likely to drop from their current values to zero within hours after the first confirmed cracks happen. Clever attackers will likely crack a large number of digital wallets quietly over weeks and months by simply capturing the encrypted transaction data, and then flash-liquidate as many wallets as they can before the scheme is discovered and values go to zero. It’ll likely happen in less than a day. North Korea, even without quantum computing, already is doing this to the tune of billions per year.

It’s highly likely governments are using record-now-crack-later strategy of recording secret communications and bank transactions now so they can uncrack them later when quantum computing is cheap and easy. It’s very likely we’ll see it used for extortion in just a few years when everyone’s communications, web traffic, and bank transactions become public knowledge. If you thought Wikileaks revealed a lot of stuff, wait until governments unencrypt years worth of recorded traffic.

He also covers the good points. There are cryptographic algorithms that are secure from quantum attack – which you should be using today. He also outlines how to detect if people are using quantum computers to start cracking things by describing the current cracking algorithms and their telltale signatures.

Still – quantum cryptographic cracking is likely to be like lightening from the blue. Everything will be fine until it’s discovered to be happening. It’s very possible that literally trillions of dollars could be stolen in the matter of hours or days.