2PP

2PP is an acronym used in multiple disciplines, and its meaning depends on context. Common usages include a safety-related rule known as the two-person policy and a technical construct called a two-party protocol.

Two-person policy: The two-person policy requires two trained personnel to be present to perform certain tasks, operate hazardous equipment, or access restricted areas. The aim is to add redundancy, improve safety, and provide immediate assistance in emergencies. The rule appears in industrial settings, laboratories, and transportation operations, and compliance is often supported by organizational procedures and regulatory requirements.

Two-party protocol: In computer science and cryptography, 2PP (often described as two-party protocols or secure two-party computation) refers to methods that allow two parties to compute a joint function over their inputs while keeping those inputs private. These protocols underpin privacy-preserving tasks such as secure voting, confidential bidding, and collaborative analytics, and they are studied within the field of secure multiparty computation for properties like security, correctness, and efficiency.

Other usages: In physics and optics, 2PP is occasionally used to denote two-photon processes or two-photon photoemission, though terminologies vary and more specific abbreviations (such as 2P or 2PPE) are common.

Because 2PP has multiple definitions, it is important to use contextual cues or explicit definitions when encountering the term in text.