As explained in the introduction, some types (Serverkey, Ciphertext) are meant to be shared with the server that performs the computations.
The easiest way to send these data to a server is to use the serialization and deserialization features. tfhe::shortint uses the serde framework. Serde's Serialize and Deserialize are then implemented on the tfhe::shortint types.
To serialize the data, we need to pick a data format. For our use case, bincode is a good choice, mainly because it is a binary format.
# Cargo.toml[dependencies]# ...bincode ="1.3.3"
// main.rsuse std::io::Cursor;use tfhe::shortint::prelude::*;fnmain() ->Result<(), Box<dyn std::error::Error>> {let (client_key, server_key) =gen_keys(PARAM_MESSAGE_2_CARRY_2_KS_PBS);let msg1 =1;let msg2 =0;let ct_1 = client_key.encrypt(msg1);let ct_2 = client_key.encrypt(msg2);letmut serialized_data =Vec::new(); bincode::serialize_into(&mut serialized_data, &server_key)?; bincode::serialize_into(&mut serialized_data, &ct_1)?; bincode::serialize_into(&mut serialized_data, &ct_2)?;// Simulate sending serialized data to a server and getting// back the serialized resultlet serialized_result =server_function(&serialized_data)?;let result:Ciphertext= bincode::deserialize(&serialized_result)?;let output = client_key.decrypt(&result);assert_eq!(output, msg1 + msg2);Ok(())}fnserver_function(serialized_data:&[u8]) ->Result<Vec<u8>, Box<dyn std::error::Error>> {letmut serialized_data =Cursor::new(serialized_data);let server_key:ServerKey= bincode::deserialize_from(&mut serialized_data)?;let ct_1:Ciphertext= bincode::deserialize_from(&mut serialized_data)?;let ct_2:Ciphertext= bincode::deserialize_from(&mut serialized_data)?;let result = server_key.unchecked_add(&ct_1, &ct_2);let serialized_result = bincode::serialize(&result)?;Ok(serialized_result)}