Note: Decaf uses its encoding isogeny to justify the equality check; the Ristretto equality check is justified not by the isogeny used in encoding, but by the Decaf isogeny to the Decaf JC. So describing it requires describing that isogeny.
(All this falls out of the explicit formulas, which don't need to care)
Note: Decaf uses its encoding isogeny to justify the equality check; the Ristretto equality check is justified not by the isogeny used in encoding, but by the Decaf isogeny to the Decaf JC. So describing it requires describing that isogeny.
(All this falls out of the explicit formulas, which don't need to care)