Encryption, Post Quantum Cryptography, Elliptic Curve, Digital Signatures, Kyber.
ct+Ay1+y2-ct =Ay1+y2 is same as the earlier commitment. As you can see this is a Zero Knowledge Proof, as Alice has proved she knows the secrets s1 and s2 without revealing them to Bob. Also similar to ECC2519Kyber hybrid mechanisms may be used where a portion of the signature could be using ECC