challenge response - SERP Analysis

https://en.wikipedia.org/wiki/Challenge%E2%80%93response_authentication

https://www.techtarget.com/searchsecurity/definition/challenge-response-system

https://www.arkoselabs.com/explained/challenge-response-authentication/

https://csrc.nist.gov/glossary/term/challenge_response_protocol

https://www.geeksforgeeks.org/computer-networks/challenge-response-authentication-mechanism-cram/

https://cnr.ncsu.edu/internalresources/it/frequently-asked-questions/challenge-response/

https://docs.yubico.com/yesdk/users-manual/application-otp/challenge-response.html

https://developer.mozilla.org/en-US/docs/Glossary/Challenge

https://www.twingate.com/blog/glossary/challenge-response

https://en.wikipedia.org/wiki/Challenge%E2%80%93response_spam_filtering