The problem is that if quantum computers are viable in 20-30 years, then we need to start using quantum-resistant algorithms today. The NSA has already admitte

The problem is that if quantum computers are viable in 20-30 years, then we need to start using quantum-resistant algorithms today. The NSA has already admitted that they are especially holding on to encrypted data for longer periods of time (and after the Utah data center, probably forever). In 20 years time they can start decrypting all that data with a quantum computer. Think about it. Today's 20 year olds, could be tomorrow's 40-50 year old politicians. All sort of juicy data could be abused then to discredit, or worse, blackmail those politicians. Right now the best weapon against it seem lattice-based encryption, so we should start working on it, so we can start using lattice-based cryptosystems within 5 years, which is a pretty small amount of time to verify this type of encryption and make it very usable, but I don't think we can afford more than that. Homomorphic encryption using lattices is something companies like Google should already be researching and trying to implement, if they really care about user privacy (and they should, because I predict an increasingly hostile movement towards Google's data mining in the future, and they need to take steps to "fix" all the privacy invasions they are currently doing with their data mining).