Clarify that PRE is one part of NuCypher hybrid cryptosystem

kms-whitepaper.tex

@@ -55,7 +55,7 @@ \section{Introduction}
 
 \kms~is a decentralized key management system (KMS), encryption, and access control service.
 It enables private data sharing between arbitrary numbers of participants in public consensus networks,
-using proxy re-encryption, a hybrid cryptosystem that combines the efficiency of symmetric encryption with the convenience of public-key encryption.
+using proxy re-encryption as part of a hybrid cryptosystem that combines the efficiency of symmetric encryption with the convenience of public-key encryption.
 Native tokens are used to incentivize network participants to perform key management and access delegation/revocation operations.
 
 \subsection{Background}