Why Proving HIBE Systems Secure is Difficult

Allison Lewko; Brent Waters

Paper 2013/068

Why Proving HIBE Systems Secure is Difficult

Allison Lewko and Brent Waters

Abstract

Proving security of Hierarchical Identity-Based Encryption (HIBE) and Attribution Based Encryption scheme is a challenging problem. There are multiple well-known schemes in the literature where the best known (adaptive) security proofs degrade exponentially in the maximum hierarchy depth. However, we do not have a rigorous understanding of why better proofs are not known. (For ABE, the analog of hierarchy depth is the maximum number of attributes used in a ciphertext.) In this work, we define a certain commonly found checkability property on ciphertexts and private keys. Roughly the property states that any two different private keys that are both ``supposed to'' decrypt a ciphertext will decrypt it to the same message. We show that any simple black box reduction to a non-interactive assumption for a HIBE or ABE system that contains this property will suffer an exponential degradation of security.

Metadata

Available format(s): PDF
Publication info: Published elsewhere. Unknown status
Contact author(s): allibishop @ gmail com
History: 2013-10-17: last of 3 revisions; 2013-02-20: received; See all versions
Short URL: https://ia.cr/2013/068
License: CC BY

BibTeX

@misc{cryptoeprint:2013/068,
      author = {Allison Lewko and Brent Waters},
      title = {Why Proving {HIBE} Systems Secure is Difficult},
      howpublished = {Cryptology {ePrint} Archive, Paper 2013/068},
      year = {2013},
      url = {https://eprint.iacr.org/2013/068}
}