RFC 2541 (rfc2541) - Page 2 of 7

DNS Security Operational Considerations

RFC 2541        DNS Security Operational Considerations       March 1999


Table of Contents

   Abstract...................................................1
   Acknowledgments............................................1
   1. Introduction............................................2
   2. Public/Private Key Generation...........................2
   3. Public/Private Key Lifetimes............................2
   4. Public/Private Key Size Considerations..................3
   4.1 RSA Key Sizes..........................................3
   4.2 DSS Key Sizes..........................................4
   5. Private Key Storage.....................................4
   6. High Level Zones, The Root Zone, and The Meta-Root Key..5
   7. Security Considerations.................................5
   References.................................................6
   Author's Address...........................................6
   Full Copyright Statement...................................7

1. Introduction

   This document describes operational considerations for the
   generation, lifetime, size, and storage of DNS cryptographic keys and
   signatures for use in the KEY and SIG resource records [RFC 2535].
   Particular attention is paid to high level zones and the root zone.

2. Public/Private Key Generation

   Careful generation of all keys is a sometimes overlooked but
   absolutely essential element in any cryptographically secure system.
   The strongest algorithms used with the longest keys are still of no
   use if an adversary can guess enough to lower the size of the likely
   key space so that it can be exhaustively searched.  Technical
   suggestions for the generation of random keys will be found in [RFC
   1750].

   Long term keys are particularly sensitive as they will represent a
   more valuable target and be subject to attack for a longer time than
   short period keys.  It is strongly recommended that long term key
   generation occur off-line in a manner isolated from the network via
   an air gap or, at a minimum, high level secure hardware.

3. Public/Private Key Lifetimes

   No key should be used forever.  The longer a key is in use, the
   greater the probability that it will have been compromised through
   carelessness, accident, espionage, or cryptanalysis.  Furthermore, if






Eastlake                     Informational