**(Decrypt.co)** Post-Quantum is a British company building an encryption algorithm resistant to quantum computers. Andersen Cheng, the founder of Post-Quantum, says he was tipped off by anonymous friends from the British intelligence world, to whom he has sold cybersecurity software since the 80s, that quantum computers produced in secrecy by governments could crack encryption within three years.

Cheng claims that unless we act soon the computerized world could devolve into “complete and utter financial collapse.” And that’s precisely what his company wants to avert. Post-Quantum believes it has created a quantum-resistant encryption protocol that banks and governments could use to re-encrypt their files, and that blockchains could use to prevent people from hacking the network.

According to CJ Tjhai, one of the co-founders of Post-Quantum and an architect of the protocol, here’s how it works.Post-Quantum’s algorithm encrypts a message by padding it out with redundant data and deliberately corrupting it with random errors. The ciphertext recipient with the correct private key knows which fluff to cut and how to correct any errors.

“You add some extra data to the file—some garbage that’s only meaningful to the private key holder. And you then also corrupt the file: you add errors to it—flip the bits,” Cheng said. It’s a little like how archivists use artificial intelligence to restore grainy videos of WW2 dogfights.

Tjhai said that this algorithm is far more secure than today’s common encryption algorithm, RSA, whose private keys are forged from the factorization of two numbers. It would take thousands of years for even the most powerful supercomputer to guess the numbers, though a quantum computer would have no problem.

Post-Quantum’s algorithm is based on an algorithm created in 1978 by Caltech professor Robert McEliece. It doesn’t require a powerful computer and is pretty fast. But it’s only feasible today because hard drives are larger and internet speeds are faster.

Tjhai said the algorithm could also protect Bitcoin.

In July, NIST announced Post-Quantum’s encryption algorithm had beaten 82 others to become one of 15 finalists of a four-year-long competition to build a quantum-resistant algorithm.