Patent ID: 10461927

Abstract:
A method of establishing a secure channel for communication between a first computing device and a second computing device is described. The method uses an elliptic curve Diffie-Hellman protocol, wherein G is an elliptic curve generator point and the first computing device has a unique private key dc with a public key Qc=dc G certified by a party trusted by the second computing device. The first computing device generates (520) a blinding factor r and sends (540) a blinded public key R=r·Qc to the second computing device. The second computing device generates (510) an ephemeral private key dt and a corresponding ephemeral public key Qt=dt G and sends Qt to the first computing device. The first computing device generates (530) Kc=KDF(r dc·Qt) and the second computing device generates (550) Kt=KDF(dt·R), where KDF is a key derivation function used in both generation operations, to establish a secure channel between the first computing device and the second computing device. G is a point in the elliptic curve group E, wherein E is a group of prime order but E* is the quadratic twist of E and is a group of order m=z·m′ where m′ is prime and z is an integer, wherein r·dc is chosen such that z is a factor of r·dc. Suitable apparatus for performing the method is also described.