APPLICATION NOTE 190

Challenge and Response with 1-Wire® SHA Devices


Abstract: Challenge-response can be a secure way of protecting access to any privileged material if implemented correctly. In this document, many options for challenge-response access control are discussed but the most secure method given is presenting a different random challenge on each access attempt and having a response that only the host can interpret without giving out any secrets. This document shows why Maxim’s SHA-1 iButtons® and 1-Wire devices are ideal choices when implementing this kind of challenge-response system.