Fix typos in ECDH and hybrid key exchange descriptions

Author: loganaden

index.bs

@@ -209,7 +209,7 @@ The most used today is ECDH, descrived in [[RFC6090]]. The main aspect of ECDH i
 
 Other common curves most used are the Montgommery curves Curve2559 and Curve448. ECDH with Curve2559 is named X25519 and ECDH with Curve448 is named X448. They are not a standard by NIST, but are widely used and recommended for their security and performance. They are defined in [[RFC7748]]. The difference betweem them is the security level and performance, with X25519 being faster and more efficient (128 security bits), while X448 offers a higher security level (224 security bits).
 
-Hybrid key exchanges combine both ECDH and post-quantum key exchange to reduce the security risks involved with post-quantum key exchanges implementations. An example is X25519MLKEM768 described in in [[X25519MLKEM768]].
+Hybrid key exchanges combine both ECDH and post-quantum key exchange to reduce the security risks involved with post-quantum key exchanges implementations. An example is X25519MLKEM768 described in [[X25519MLKEM768]].
 
 Note: The output of a key exchange generally is not uniformly distributed, therefore it is descouraged using that as cryptographic key. Instead, a KDF is required to derive a symmetric key from the shared secret.