This White Paper describes the high-level technical features, motivations and use cases for ETSI TC CYBER’s new middlebox standards, known collectively as the ‘Middlebox Security Protocols’ or ‘MSP’. The Middlebox Security Protocol standards suite redefines middlebox operations and network security. MSP comprises three Parts so far: TS 103 523, Part 1 [1] is a framework that defines the security properties of MSP; TS 103 523, Part 2 [2] is a protocol that specifies user-controlled access to data and fine-grained control over middlebox access; TS 103 523, Part 3 [3] is a protocol driven by industry need to still perform vital data centre operations, after changes to a major internet protocol (TLS) removed this important functionality.