SIDH

SIDH Library is a fast and portable software library that implements a new suite of algorithms for supersingular isogeny Diffie-Hellman key exchange [1]. The chosen parameters aim to provide 128 bits of security against attackers running a large-scale quantum computer, and 192 bits of security against classical algorithms. SIDH has the option of a hybrid key exchange that combines supersingular isogeny Diffie-Hellman with a high-security classical elliptic curve Diffie-Hellman key exchange at a small overhead. SIDH is the first supersingular isogeny Diffie-Hellman software that is fully protected against timing and cache attacks: all operations on secret data run in constant time. The library is also significantly faster than previous implementations, e.g., it is about 2.5 times faster than the previously best (non-constant-time) supersingular isogeny Diffie-Hellman software