Is there a common scheme for a broadcast style encryption that doesn't involve and exchange of a common key? I'm aware that traditionally what would be done is there would be a common symmetrical key that is given to all parties and exchanged securely using the recipients public key.
I'm building an application on the Ethereum blockchain where I want to securely transmit information to all recipients involved using one message. Unfortunately this means key revoking becomes an expensive process due to Ethereum transaction costs as I would have to redistribute a new symmetric key to all recipients again.
Is there any way I could encrypt a message using a set of public keys that could be decrypted by any of their respective private keys so that revocation is not so expensive? I would simply just not include the revoked public key next time I send an update. The message is quite a small amount of text, so size should also not be a problem.
Apologies if this is a noob question, this is my first fore into this type of encryption. Thanks!