7.5 Cryptographic Algorithms

All meeting data sent over UDP gets encrypted with AES in GCM mode [11]. Key derivation uses the HKDF algorithm [13]. For public key encryption and signing, we rely on Diffie-Hellman over Curve25519 [4] and EdDSA over Ed25519 [5]. We use the interface and implementation of the NaCl [6]-inspired libsodium library [9], as detailed below.