Lead Report / History

NULL Was a Negotiated Choice. The Packet Did Not Advertise That Choice
RFC 2410 gave IPsec an encryption algorithm that changed no bit at all. That apparent joke solved a serious interoperability problem: two endpoints could agree explicitly to use ESP for integrity without confidentiality. Yet the same ordinary ESP packet did not give an intermediate observer a deterministic way to know that the payload was unencrypted—and visibility still did not confer permission to inspect it.











