The NULL Encryption Algorithm and Its Use With IPsec (RFC2410)
Original Publication Date: 1998-Nov-01
Included in the Prior Art Database: 2019-Feb-11
Internet Society Requests For Comment (RFCs)
R. Glenn: AUTHOR [+1]
This memo defines the NULL encryption algorithm and its use with the IPsec Encapsulating Security Payload (ESP). [STANDARDS-TRACK]
Network Working Group R. Glenn Request for Comments: 2410 NIST Category: Standards Track S. Kent BBN Corp November 1998
The NULL Encryption Algorithm and Its Use With IPsec
Status of this Memo
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (1998). All Rights Reserved.
This memo defines the NULL encryption algorithm and its use with the IPsec Encapsulating Security Payload (ESP). NULL does nothing to alter plaintext data. In fact, NULL, by itself, does nothing. NULL provides the means for ESP to provide authentication and integrity without confidentiality.
Further information on the other components necessary for ESP implementations is provided by [ESP] and [ROAD].
This memo defines the NULL encryption algorithm and its use with the IPsec Encapsulating Security Payload [ESP] to provide authentication and integrity without confidentiality.
NULL is a block cipher the origins of which appear to be lost in antiquity. Despite rumors that the National Security Agency suppressed publication of this algorithm, there is no evidence of such action on their part. Rather, recent archaeological evidence suggests that the NULL algorithm was developed in Roman times, as an exportable alternative to Ceaser ciphers. However, because Roman numerals lack a symbol for zero, written records of the algorithm’s development were lost to historians for over two millennia.
Glenn & Kent Standards Track [Page 1]
RFC 2410 NULL and IPsec November 1998
[ESP] specifies the use of an optional encryption algorithm to provide confidentiality and the use of an optional authentication algorithm to provide authentication and integrity. The NULL encryption algorithm is a convenient way to represent the option of not applying encryption. This is referred to as ESP_NULL in [DOI].
The IPsec Authentication Header [AH] specification provides a similar service, by computing authentication data which covers the data portion of a packet as well as the immutable in transit portions of the IP header. ESP_NULL does not include the IP header in calculating the authentication data. This can be useful in providing IPsec services through non-IP network devices. The discussion on how ESP_NULL might be used with non-IP network devices is outside the scope of this document.
In this memo, NULL is used within the context of ESP. For further information on how the various pieces of ESP fit together to provide security services, refer to [ESP] and [ROAD].
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC 211...