Update draft-irtf-cfrg-bbs-signatures.md

Co-authored-by: Andrew Whitehead <[email protected]>

Author: BasileiosKal

draft-irtf-cfrg-bbs-signatures.md

@@ -1697,7 +1697,7 @@ For certain types of message values, set membership proofs (for example, [@VB22]
 
 ## Validating Public Keys
 
-Note that all core operations as defined in (#core-operations) expect the Signer's public key as input. It is RECOMMENDED for all those operations, that they deserialize the public key first using the `octets_to_pubkey` procedure defined in (#octets-to-public-key), even if they only require the octet string representation of the public key. If the `octets_to_pubkey` procedure returns INVALID, the calling operation should also return INVALID and abort. This recommendation applies is the `CoreSign` ((#coresign)) and `CoreProofGen` ((#coreproofgen)) operations. An explicit invocation to the `octets_to_pubkey` operation is already defined and therefore required in the `CoreVerify` ((#coreverify)) and `CoreProofVerify` ((#coreproofverify)) operations. In case that the required checks for the validity of the Signer's public key are not performed, the results are unpredicted, causing unexpected vulnerabilities (for example, the output of the pairing operation on input an invalid elliptic curve point can be highly iregural and implementation dependant, with some returning the identity point of the elliptic curve and others returnong errors).
+Note that all core operations as defined in (#core-operations) expect the Signer's public key as input. It is RECOMMENDED for all those operations, that they deserialize the public key first using the `octets_to_pubkey` procedure defined in (#octets-to-public-key), even if they only require the octet string representation of the public key. If the `octets_to_pubkey` procedure returns INVALID, the calling operation should also return INVALID and abort. This recommendation applies is the `CoreSign` ((#coresign)) and `CoreProofGen` ((#coreproofgen)) operations. An explicit invocation to the `octets_to_pubkey` operation is already defined and therefore required in the `CoreVerify` ((#coreverify)) and `CoreProofVerify` ((#coreproofverify)) operations. If the required checks for the validity of the Signer's public key are not performed, the results are unpredictable, leading to unexpected vulnerabilities (for example, the output of the pairing operation on input of an invalid elliptic curve point can be highly irregular and implementation-dependent, with some returning the identity point of the elliptic curve and others returning errors).
 
 ## Skipping Membership Checks