Hm, with regard to timing attacks, I’m not talking about clearing the cofactor, but rather setting the most significant bit to zero & the second most significan

Hm, with regard to timing attacks, I’m not talking about clearing the cofactor, but rather setting the most significant bit to zero & the second most significant to one. My understanding is that this is to defend against an insecure implementation of the scalar multiplication operation which takes a varying length of time depending on which bit is the first non-zero one, thereby revealing information about the key. The linked article supports this (I believe), but I’m always happy to be corrected about these kinds of things :)