RFC 1825 (rfc1825) - Page 2 of 22

Security Architecture for the Internet Protocol

RFC 1825              Security Architecture for IP           August 1995


   Non-repudiation
           The property of a receiver being able to prove that the sender
           of some data did in fact send the data even though the sender
           might later desire to deny ever having sent that data.

   SPI
           Acronym for "Security Parameters Index".  An unstructured
           opaque index which is used in conjunction with the
           Destination Address to identify a particular Security
           Association.

   Security Association
           The set of security information relating to a given network
           connection or set of connections.  This is described in
           detail below.

   Traffic Analysis
           The analysis of network traffic flow for the purpose of
           deducing information that is useful to an adversary.
           Examples of such information are frequency of transmission,
           the identities of the conversing parties, sizes of packets,
           Flow Identifiers used, etc. [Sch94].

1.2 Requirements Terminology

   In this document, the words that are used to define the significance
   of each particular requirement are usually capitalised.  These words
   are:

   - MUST

      This word or the adjective "REQUIRED" means that the item is an
      absolute requirement of the specification.

   - SHOULD

      This word or the adjective "RECOMMENDED" means that there might
      exist valid reasons in particular circumstances to ignore this
      item, but the full implications should be understood and the case
      carefully weighed before taking a different course.

   - MAY

      This word or the adjective "OPTIONAL" means that this item is
      truly optional.  One vendor might choose to include the item
      because a particular marketplace requires it or because it
      enhances the product, for example; another vendor may omit the
      same item.



Atkinson                    Standards Track