I am trying to understand the Networking And Cryptography Library (NaCL).
Consider i have a file that i want to send to multiple recipients. PGP or S/MIME supports multiple recipients by encrypting the file with a single symmetric key and encrypting this symmetric key with the public keys of the recipients. is this task easily achieved with NaCL as well? How? Thanks for hints.
Update One idea i had is to do it similar to pgp. Calculate the exchange keys of my own private key and the public keys of the recipients. Create one symmetric key. Encrypt file file symmetric key. Encrypt symmetric key with each exchange key. send encrypted file and encrypted symmetric key to recipient.
The main reason for this: i want to upload the encrypted file only once to a server where the recipients can download them.