Would asymmetric cryptography be feasible in World War II? Assuming people in the forties would have known asymmetric cryptographic methods like RSA, would they have been able to make sensible use of them?
There were no real electronic computers at the time, but the things achieved in Bletchley Park and elsewhere mean that some processes could have been automatised.
Sure, you can do Diffie-Hellman or RSA by hand if you have to.
And you don't need the bit length we use today with powerful adversaries.
I'm not an expert on WW2 computational machines but I won't be surprised if something to do modular exponentiation could be built using WW2 technology given sufficient motivation.
A modern cryptographer in WW2 could make truly unbreakable ciphers. With authentication, key exchange, good randomness, and all the good stuff we have now.