Update draft-ietf-lamps-pq-composite-sigs.md

Add definition of new Signature methods

draft-ietf-lamps-pq-composite-sigs.md

@@ -164,23 +164,15 @@ This document defines combinations of ML-DSA [FIPS.204] in hybrid with tradition
 --- middle
 
 
-# Changes in -03
+# Changes in -04
 
 Interop-affecting changes:
 
-* Compacted CompositeSignaturePrivateKey to SEQUENCE SIZE (2) OF OCTET STRING instead of OneAsymmetricKey to remove redundancy
-* Added support for the ML-DSA context String, and use the Composite Domain as the context for the underlying ML-DSA component algorithm.
-* Added Pre-Hash and Pure modes and changed the Message format to align with FIPS-204.  This breaks backwards compatibility with all previous versions.
-* Updated the OID table for new Pre-Hash OIDs and added them to the IANA section.
-* Updated Use in CMS section to reflect content is hashed and pure Composite ML-DSA should be used.
+* Removed the ASN.1 around the DER encoding
 
 Editorial changes:
 
-* Added the ASN.1 encodings for the component public keys and signature algorithm identifiers
-* ASN.1 Module changes:
-  * Renamed the module from Composite-Signatures-2023 -> Composite-MLDSA-2024
-  * Simplified the ASN.1 module to make it more compiler-friendly (thanks Carl!) -- should not affect wire encodings.
-* Updated Security Considerations about Non-separability, EUF-CMA and key reuse.
+
 
 
 # Introduction {#sec-intro}
@@ -261,6 +253,18 @@ Composite schemes are defined as cryptographic primitives that consist of three
       of the Message.  If the signature and public key cannot verify the Message,
       it returns false.
 
+We define the following algorithms which we use to serialize and deserialize the public and private keys
+
+   *  `SerializeKey(key) -> bytes`: Produce a fixed-length byte string encoding the public or private key.
+
+   *  `DeserializeKey(bytes) -> pk`: Parse a fixed-length byte string to recover a public or private key. This function can fail if the input byte string is malformed.
+
+We define the following algorithms which are used to serialize and deseralize the compsoite signature value
+
+   *  `SerializeSignature(key) -> bytes`: Produce a fixed-length byte string encoding the public or private key.
+
+   *  `DeserializeKey(bytes) -> pk`: Parse a fixed-length byte string to recover a public or private key. This function can fail if the input byte string is malformed.
+
 A composite signature allows the security properties of the two underlying algorithms to be combined via standard signature operations `Sign()` and `Verify()`.
 
 This specification uses the Post-Quantum signature scheme ML-DSA as specified in [FIPS.204] and {{I-D.ietf-lamps-dilithium-certificates}}. For Traditional signature schemes, this document uses the RSA PKCS#1v1.5 and RSA-PSS algorithms defined in [RFC8017], the Elliptic Curve Digital Signature Algorithm ECDSA scheme defined in section 6 of [FIPS.186-5], and Ed25519 / Ed448 which are defined in [RFC8410]. A simple "signature combiner"function which prepends a domain separator value specific to the composite algorithm is used to bind the two component signatures to the composite algorithm and achieve weak non-separablity.