Surprised? Probably not. According to recent documents from Edward Snowden, the National Security Agency is spending $79.7 million on a research program called “Penetrating Hard Targets”. This project involves building a quantum computer that would be able to break most types of encryption. At the moment, the agency is nowhere near completion of the project, so no need to worry yet. However, the NSA is already pretty good at breaking encryption and bribes companies to promote flawed encryption, so with this much power and money, it doesn’t seem too far-fetched that the NSA will successfully build this computer.
This poses a threat to Bitcoin and other cryptocurrencies. Bitcoin relies on the SHA-256 algorithm (which was designed by the NSA). SHA-256 is considered very strong, but if it were to be broken (assuming the NSA doesn’t already have a backdoor), Bitcoin can shift to a stronger algorithm. However, if the NSA successfully builds a computer that can crack most types of encryption, Bitcoin and the NSA might have to play a constant cat-and-mouse game where Bitcoin shifts to a stronger type of encryption and then the NSA breaks it, which could damage the overall Bitcoin network and security.
There’s really no need to be paranoid and worried at the moment. Large-scale quantum computing is still years, maybe decades away. Who knows what state Bitcoin will be in at that time. However, it doesn’t hurt to be prepared.