Security in Computing 5th Edition by Shari Lawrence Pfleeger, Charles P Pfleeger, Jonathan Margulies

Exercise 38

Discuss the tradeoffs between a manual challenge response system (one to which the user computes the response by hand or mentally) and a system that uses a special device, like a calculator.

Step 1 of 2

Challenge Response Systems

A manual challenge response system is a challenge and response system that allows the user to manually compute the response. An example of such a system is the additional verification signature at the back of a bank check.

In contrast, an automated or electronic device, such as a calculator allows the user to electronically respond to a challenge. An example of such a system is the ATM machines which are placed by banks to primarily allow automated telling.