Jayjay
Contributor
- Joined
- Apr 7, 2002
- Messages
- 7,173
- Location
- Finland
- Basic Beliefs
- An accurate worldview or philosophy
I think a lot of he current financial and communications is based on public key cryptography, which mathematically is just functions that are really hard to calculate in one way, but trivial to reverse. For example, multiplying large prime numbers is a quick calculation for a computer, but factorizing said number back to prime numbers is practically impossible for any traditional computers, as long as the factors are large enough.
However, with a quantum computer one could in theory cheat and do the factorization in "parallel" because qubits are in a superposititon of all possible states, and as such really break all the existing cryptographical infrastructure. Currently I think they've onlymanaged to hold only a few qubits per calculation but when engineering issues are resolved, and no doubt they will be, what will that mean in practice to all our security?
For example, all the cryptocurrency based on PKI would become trivial to hack and forge. No more bitcoin. And without PKI, there is no way to sign one's messages or communications with a private key, so all security based on that would be meaningless.
This is where my imagination stops. What other alternatives for public key infrastructure is there? Are there some mathematical issues that can be made hard to crack even with quantum computers? Do we all need to start relying on quantum security by entangling the bits we communicate to shield them from tampering? Or go back to just symmetric cryptography and ensuring we use secure, maybe physical channels to exchange our encryption keys? Or what?
However, with a quantum computer one could in theory cheat and do the factorization in "parallel" because qubits are in a superposititon of all possible states, and as such really break all the existing cryptographical infrastructure. Currently I think they've onlymanaged to hold only a few qubits per calculation but when engineering issues are resolved, and no doubt they will be, what will that mean in practice to all our security?
For example, all the cryptocurrency based on PKI would become trivial to hack and forge. No more bitcoin. And without PKI, there is no way to sign one's messages or communications with a private key, so all security based on that would be meaningless.
This is where my imagination stops. What other alternatives for public key infrastructure is there? Are there some mathematical issues that can be made hard to crack even with quantum computers? Do we all need to start relying on quantum security by entangling the bits we communicate to shield them from tampering? Or go back to just symmetric cryptography and ensuring we use secure, maybe physical channels to exchange our encryption keys? Or what?
