International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Identity-Based Encryption Secure under Selective Opening Attack

Mihir Bellare
Brent Waters
Scott Yilek
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Abstract: We present the first Identity-Based Encryption (IBE) scheme that is proven secure against selective opening attack (SOA). This means that if an adversary, given a vector of ciphertexts, adaptively corrupts some fraction of the senders, exposing not only their messages but also their coins, the privacy of the unopened messages is guaranteed. Achieving security against such attacks is well-known to be challenging and was only recently solved in the PKE case via lossy encryption. We explain why those methods wonÂ’t work for IBE and instead rely on an approach based on encryption schemes that have a property we call one-sided public openability. Our SOA-secure IBE scheme is quite efficient and proven secure without random oracles based on the Decision Linear assumption.
  title={Identity-Based Encryption Secure under Selective Opening Attack},
  booktitle={IACR Eprint archive},
  keywords={identity-based encryption, selective opening attacks},
  note={ 14692 received 24 Mar 2010},
  author={Mihir Bellare and Brent Waters and Scott Yilek},