International Journal of Information and Electronics Engineering
Various situations exist in which enhanced security procedures require that two or more people work together and authenticate at the same time. For example, police personnel or security guards carrying cash must always work in pairs so that if one of them is incapacitated, the other person can complete the mission. In principle, this also enables one partner to stop the other from carrying out any illegal act. However, the question remains as to how a manager can verify that two people are actually working together.