Is there a standard format for storing/exchanging encrypted data along with the key needed to decrypt it (data is encrypted with a single use symmetric key and the symmetric key itself is encrypted with asymmetric key for the receiver)?
We are trying to build an interoperable protocol to exchange large messages between two parties that may not agree on much else besides using asymmetric keys. The best way seems to be using a symmetric single use key to encrypt the data and then encrypt it with the asymmetric key and pass along the whole thing as a package (e.g. RSA wrapped AES). So is there any widely used standard for sharing the encrypted text along with its key, preferably along with some information about the symmetric algorithm used.
The only work that I found in that direction is OpenPGP which is somewhat too implementation specific. I was wondering if there is anything else that has more metadata along with it to describe the alogs and the keys.