> To me what is most surprising is that the attack seemingly came out of nowhere,
This wasn't my understanding at all. The specific issue in isogeny based cryptography which the attack exploits has been a source of worry in the cryptographic community for a while, and is exactly why NIST put SIKE in the "for further consideration & crypt-analysis" category when making their standardization decisions.
This wasn't my understanding at all. The specific issue in isogeny based cryptography which the attack exploits has been a source of worry in the cryptographic community for a while, and is exactly why NIST put SIKE in the "for further consideration & crypt-analysis" category when making their standardization decisions.