Introduction overhaul

draft-ietf-cose-merkle-tree-proofs.md

@@ -71,12 +71,11 @@ The extensibility of the approach is demonstrated by providing CBOR encodings fo
 
 # Introduction
 
-Merkle trees are one of many verifiable data structures that enable tamper evident secure information storage, through their ability to protect the integrity of batches of documents or collections of statements.
-Merkle trees can be constructed from simple operations such as concatenation and digest via a cryptographic hash function, however, more advanced constructions enable proofs of different properties of the underlying verifiable data structure.
-Verifiable data structure proofs can be used to prove a document is in a database (proof of inclusion), that a database is append only (proof of consistency), that a smaller set of statements are contained in a large set of statements (proof of disclosure, a special case of proof of inclusion), or proof that certain data is not yet present in a database (proofs of non inclusion).
-Differences in the representation of verifiable data structures, and verifiable data structure proof types, can increase the burden for implementers, and create interoperability challenges for transparency services.
-This document describes how to convey verifiable data structures, and associated proof types in COSE envelopes.
-For conciseness, a COSE object securing a verifiable data structure and its associated proofs, is referred to as a COSE Receipt.
+COSE Receipts are signed proofs that include metadata about about certain states of a verifiable data structure (VDS) that are true when the COSE Receipt was issued.
+COSE Receipts can include proves that a document is in a database (proof of inclusion), that a database is append only (proof of consistency), that a smaller set of statements are contained in a large set of statements (proof of disclosure, a special case of proof of inclusion), or proof that certain data is not yet present in a database (proofs of non inclusion).
+Different VDS can produce different verifiable data structure proofs (VDP).
+The combination of representations of various VDS and VDP can significantly increase burden for implementers and create interoperability challenges for transparency services.
+This document describes how to convey VDS and associated VDP types in unified COSE envelopes.
 
 ## Requirements Notation