Medusa is meant to support different platforms and different encryption algorithms over time. Therefore, Medusa has the notion of a suite, that contains all informations regarding the type of curve and encryption used. This notion is similar to the cipher suites defined in the TLS specifications.
EncryptionOracle is tied to a specific suite so the dapp knows which suite
has been used to encrypt any ciphertext.
Currently there is only one suite supported on Medusa using the bn254 curve. Later, Medusa will switch to using BLS12-381 and therefore offer better security with better standards.
This suite is the default one. It uses BN254 as the main curve, where the public key of the Medusa network is defined over the group G1 and it uses a an Hash El Gamal encryption algorithm where the hash is SHA256.