rev 02 documentation for SignerCore and StmSigner

mithril-stm/src/stm.rs

@@ -167,8 +167,11 @@ pub struct StmInitializer {
     pub(crate) pk: StmVerificationKeyPoP,
 }
 
-/// Participant in the protocol can sign messages.
-/// This instance can only be generated out of an `StmInitializer`.
+/// Core signer in the protocol can sign messages.
+/// A full-node verifier does not need to receive the registration information
+/// of a signature, since it has all the identities already.
+/// So, the signatures to be verified by a full-node verifier can be generated by
+/// the signers that do not contain `closed_reg`.
 #[derive(Debug, Clone)]
 pub struct SignerCore {
     mt_index: u64,
@@ -178,7 +181,8 @@ pub struct SignerCore {
     vk: StmVerificationKey,
 }
 
-/// Participant in the protocol can sign messages.
+/// Participant in the protocol can sign messages that depend on `closed_reg`.
+/// So, `StmSigner` is built on `SignerCore` with one additional field: `ClosedKeyReg`.
 /// This instance can only be generated out of an `StmInitializer` and a `ClosedKeyReg`.
 /// This ensures that a `MerkleTree` root is not computed before all participants have registered.
 #[derive(Debug, Clone)]