  Currently, public-key compression of supersingular isogeny Diffie-Hellman
(SIDH) and its variant, supersingular isogeny key encapsulation (SIKE) involve
pairing computation and discrete logarithm computation. In this paper, we
propose novel methods to compute only 3 discrete logarithms instead of 4, in
exchange for computing a lookup table efficiently. The algorithms also allow us
to make a trade-off between memory and efficiency. Our implementation shows
that the efficiency of our algorithms is close to that of the previous work,
and our algorithms perform better in some special cases.
