DES was broken about 23 years after it was designed.
I'd be surprised if 30 years into the future (probably earlier given the incentives we have to break crypto today are so much than those we had in '98) if these algorithms weren't broken.
There is actually no precedent of a cryptographic system relying on computational hardness surviving for more than a generation. And given that our fundamental theoretical understanding hasn't really evolved beyond, "we think a bunch of these problems are hard", things are likely to stay that way for a while.
That's an oversimplification. The field of cryptography has advanced by orders of magnitude since DES and RC4. Each time one of those breaks, we abstract the weakness into a class of vulnerability that the next algorithm will be immune to.
>There is actually no precedent of a cryptographic system relying on computational hardness surviving for more than a generation.
That's because cryptosystems relying on computational hardness aren't that old.
>And given that our fundamental theoretical understanding hasn't really evolved beyond, "we think a bunch of these problems are hard", things are likely to stay that way for a while.
These assumptions haven't really broken though. You give an example of DES, but that doesn't rely on computational hardness assumptions. Asymmetric crypto with a trapdoor function does. There hasn't even been a big breakthrough in the original prime number factorization assumptions of RSA/DH.
I'd be surprised if 30 years into the future (probably earlier given the incentives we have to break crypto today are so much than those we had in '98) if these algorithms weren't broken.
There is actually no precedent of a cryptographic system relying on computational hardness surviving for more than a generation. And given that our fundamental theoretical understanding hasn't really evolved beyond, "we think a bunch of these problems are hard", things are likely to stay that way for a while.