Blom's scheme

Blom's scheme is a symmetric threshold key exchange protocol in cryptography. The scheme was proposed by the Swedish cryptographer Rolf Blom in a series of articles in the early 1980s.[1][2]

A trusted party gives each participant a secret key and a public identifier, which enables any two participants to independently create a shared key for communicating. However, if an attacker can compromise the keys of at least k users, they can break the scheme and reconstruct every shared key. Blom's scheme is a form of threshold secret sharing.

Blom's scheme is currently used by the HDCP (Version 1.x only) copy protection scheme to generate shared keys for high-definition content sources and receivers, such as HD DVD players and high-definition televisions.[3]

  1. ^ Blom, Rolf. Non-public key distribution. In Proc. CRYPTO 82, pages 231–236, New York, 1983. Plenum Press
  2. ^ Blom, Rolf. "An optimal class of symmetric key generation systems", Report LiTH-ISY-I-0641, Linköping University, 1984 [1]
  3. ^ Crosby, Scott; Goldberg, Ian; Johnson, Robert; Song, Dawn; Wagner, David (2002). "A Cryptanalysis of the High-Bandwidth Digital Content Protection System". Security and Privacy in Digital Rights Management. Lecture Notes in Computer Science. Vol. 2320. pp. 192–200. CiteSeerX 10.1.1.10.9307. doi:10.1007/3-540-47870-1_12. ISBN 978-3-540-43677-5. {{cite book}}: |journal= ignored (help)