Challenge-Response Authentication

Definition - What does Challenge-Response Authentication mean?

Challenge-response authentication is a group or family of protocols characterized by one entity sending a challenge to another entity. The second entity must respond with the appropriate answer to be authenticated.

A simple example of this is password authentication. The challenge is from a server asking the client for a password to authenticate the client's identity so that the client can be served.

Techopedia explains Challenge-Response Authentication

Most smart card systems use challenge-response authentication. These systems require at least two things for authentication and entry: the smart card and the user’s password.

Another challenge-response authentication example is the use of CAPTCHA, a form of reverse-Turing test for the system to determine if the client is a human or not. This is used to prevent spam and auto-registration of new accounts for a website or email.

Biometric systems are another form of challenge-response authentication.

In cryptography, zero-knowledge password proof and key agreement systems such as secure remote password, CRAM-MD5 and secure shell's challenge-response system based on RSA are considered to be very sophisticated challenge-response algorithms.

Posted by:

Connect with us

Techopedia on Linkedin
Techopedia on Linkedin
Tweat cdn.techopedia.com
Techopedia on Twitter


'@Techopedia'
Sign up for Techopedia's Free Newsletter!
Techwise Webinar Series
Understanding the Big Data Landscape
Understanding the Big Data Landscape
Big Data is everywhere, that's for sure. But the big question for today's savvy enterprise is: exactly where does Big Data fit into your organization?

Email Newsletter

Join 138,000+ IT pros on our weekly newsletter

Resources
Free Whitepaper – Bridging the IT Operations Application Owner Gap
Free Whitepaper – Bridging the IT Operations Application Owner Gap:
Conflicting organizational needs all too often create tension between functional silos. Application owners demand more and more resources.
Free 30 Day Trial – VMTurbo Operations Manager
Free 30 Day Trial – VMTurbo Operations Manager:
VMTurbo's flagship product, Operations Manager maintains your virtual and cloud environments in a healthy state. It manages homogeneous and...