International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: HAIL: A High-Availability and Integrity Layer for Cloud Storage

Kevin D. Bowers
Ari Juels
Alina Oprea
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Abstract: We introduce HAIL (High-Availability and Integrity Layer), a distributed cryptographic system that permits a set of servers to prove to a client that a stored file is intact and retrievable. Proofs in HAIL are efficiently computable by servers and highly compact---typically tens or hundreds of bytes, irrespective of file size. HAIL cryptographically verifies and reactively reallocates file shares. It is robust against an active, mobile adversary, i.e., one that may progressively corrupt the full set of servers. We propose a strong, formal adversarial model for HAIL, and rigorous analysis and parameter choices. We also report on a prototype implementation. HAIL strengthens, formally unifies, and streamlines distinct approaches from the cryptographic and distributed-systems communities. HAIL also includes an optional new tool for proactive protection of stored files. HAIL is primarily designed to protect static stored objects, such as backup files or archives.
  title={HAIL: A High-Availability and Integrity Layer for Cloud Storage},
  booktitle={IACR Eprint archive},
  keywords={cryptographic protocols / storage security,  proofs of retrievability, erasure coding},
  note={ Alina Oprea ( 14252 received 20 Nov 2008, last revised 8 Jan 2009},
  author={Kevin D. Bowers and Ari Juels and Alina Oprea},