In today's connected world, understanding trust is more critical than ever. Trust Verification Systems examines how we assess trustworthiness using approaches like signaling theory, reputation systems, and awareness of our cognitive biases. It provides a framework for understanding the subtle processes that shape our perceptions, emphasizing that effective trust verification relies on accurate signals and awareness of our limitations. For example, signaling theory suggests that observable actions communicate trustworthiness, while reputation systems aggregate past behavior to influence future interactions. The book explores how humans have adapted trust verification methods, from relying on communal knowledge in tribal societies to utilizing algorithms on modern online platforms; it investigates cognitive biases such as the halo effect, which can skew our evaluations. The book progresses through foundational principles, signaling theory, reputation systems, and cognitive biases, ultimately offering actionable recommendations for improving trust judgments. This comprehensive approach integrates insights from psychology, economics, and computer science to offer a nuanced understanding of trust in various contexts.