What term refers to unintended signals or noise appearing external to communications equipment?

The term that refers to unintended signals or noise appearing external to communications equipment is emanation. Emanation in this context pertains to any unintentional signals that can escape from electronic devices, which may contain sensitive information. This concept is critical in the field of cybersecurity, particularly when considering information security and the protection of data from surveillance or interception. Understanding emanations is vital for implementing countermeasures against potential threats, ensuring that sensitive data is not revealed through unintended outputs from communication devices.

Emulation refers to the ability of a system to imitate another system's functions, often used in contexts like software or systems design. A signature can denote a unique identifier in traffic patterns or data packets, frequently relevant in cybersecurity for detecting malware. Salutation, while a term commonly used in communication, typically refers to a greeting or polite expression and is unrelated to the context of electronic signals or security.