Here, I would like to continue about xor issue for other paper.
Wong and Chan proposed a ‘Mutual authentication and key exchange for low power wireless communications', then Kyungah Shim firstly presented a cryptanalysis (Cryptanalysis of mutual authentication and key exchange for low power wireless communications.pdf ). Later, Siaw-Lynn Ng and Chris Mitchell also gave a comment (Comments on mutual authentication and key exchange protocols for low power wireless.pdf). The other one scholar pointed out a verity attack (On the security of mutual authentication and key exchange for low power wireless communications.pdf).
According to our discussion last time, our method may be easily, directly, and more efficiently to success attack.
σ= rA ⊕ y.
Thus, we can make a new one where σ= (-rA ⊕ -y).
This is a original equation in Wong-Chan scheme.
According our method, we can rewrite to the other one, and obtain the same result.