Why is that? I think it is entirely possible that in the future, encryption techniques used today will become compromised as both computing power improves and/

Why is that? I think it is entirely possible that in the future, encryption techniques used today will become compromised as both computing power improves and/or flaws are discovered. If someone is holding ciphertext encrypted with a compromised algorithm, then it could be decrypted. Basically, how do you know what we are encrypting today, won't be able to have the encryption broken 30 or 50 years from now?