Update draft-ietf-oauth-attestation-based-client-auth.md

Co-authored-by: Giuseppe De Marco <[email protected]>

draft-ietf-oauth-attestation-based-client-auth.md

@@ -108,7 +108,7 @@ Client Instance:
 : A deployed instance of a piece of client software.
 
 Client Instance Key:
-:  A cryptographic, asymmetric key generated by the Client Instance and proven to the client backend. The public key is contained in the Client Attestation JWT and is used to sign the Client Attestation Proof of Possession.
+:  A cryptographic asymmetric key pair that is generated by the Client Instance where the public key of the key pair is provided to the client backend. This public key is then encapsulated within the Client Attestation JWT and is utilized to sign the Client Attestation Proof of Possession.
 
 # Client Attestation