Chapter

Advances in Cryptology – CRYPTO 2010

Volume 6223 of the series Lecture Notes in Computer Science pp 98-115

Lattice Basis Delegation in Fixed Dimension and Shorter-Ciphertext Hierarchical IBE

  • Shweta AgrawalAffiliated withLancaster UniversityUniversity of Texas, Austin
  • , Dan BonehAffiliated withLancaster UniversityStanford University
  • , Xavier BoyenAffiliated withLancaster UniversityUniversité de Liège

Abstract

We present a technique for delegating a short lattice basis that has the advantage of keeping the lattice dimension unchanged upon delegation. Building on this result, we construct two new hierarchical identity-based encryption (HIBE) schemes, with and without random oracles. The resulting systems are very different from earlier lattice-based HIBEs and in some cases result in shorter ciphertexts and private keys. We prove security from classic lattice hardness assumptions.