Crypto API: encrypt with the private-key, then decrypt with the public-key

[Mavis J]

Hello experts, I have a peculiar problem.

Currently, my application generates an asymmetric key pair using the CryptGenKey function with the Algid parameter set to AT_KEYEXCHANGE. The application can then successfully encrypt using the public-key, and decrypt using the private-key.

However, my requirement for usage is to encrypt with the private-key, then decrypt with the public-key. If I'm correct, this should be a fairly common method for secure data sharing between a client and a host. The receiver usually only has the public key and not the private key; since in RSA, the public key can be generated with the private key; but not vice versa.

So, is my requirement possible with the CryptoAPI framework?

Cheers