The WATA Family

Abstract

In this chapter, we focus on a family of computer-assisted exam protocols called WATA, which stands for Written Authenticated Though Anonymous exams. A common characteristic of all WATA protocols is the traditional testing procedure, which is face-to-face. The difference among the WATA protocols is that each version provides a different level of computer assistance. Additionally, each protocol of the family has some slightly different functional requirement and threat model with respect to the others. One protocol considers local tasks, such as notification of marks, and no TTP. Some others consider remote tasks, such as remote registration, but assume TTP. Another achieves remote tasks without TTP. In some way, Remark! already makes remote registration and remote notification with minimal reliance on trusted parties. As Remark! belongs to the class of Internet-based exams, it mandates candidate and exam authority to use computers at testing to sign and encrypt the tests. Therefore, testing cannot take place by pen and paper. Moreover, Remark! assumes at least one honest mix server. As we shall see later, there exists a version of WATA that ensures the same authentication and privacy requirements of Remark! without the need to rely on mixnet or TTP.