Authors:
Kaibin Huang
1
;
Yu-Chi Chen
2
and
Raylin Tso
1
Affiliations:
1
National Chengchi University, Taiwan
;
2
Institute of Computer Science and Academic Sinica, Taiwan
Keyword(s):
Cloud Storage, Equality Test, Filtered Equality Test, Public Key Encryption, Secret Sharing, Semantic Security.
Related
Ontology
Subjects/Areas/Topics:
Applied Cryptography
;
Cryptographic Techniques and Key Management
;
Data Engineering
;
Databases and Data Security
;
Information and Systems Security
;
Security and Privacy in the Cloud
;
Security Protocols
Abstract:
Cloud storage allows users to outsource their data to a storage server. For general security and privacy concerns,
users prefer storing encrypted data to pure ones so that servers do not learn anything about privacy.
However, there is a natural issue that servers have worked some analyses (i.e. statistics) or routines for encrypted
data without losing privacy. In this paper, we address the basic functionality, equality test, over
encrypted data, which at least can be applied to specific analyses like private information retrieval. We introduce
a new system, called filtered equality test, which is an additional functionality for existing public key
encryption schemes. It satisfies the following scenario: a ciphertext-receiver selects several messages as a set
and produces its related warrant; then, on receiving this warrant, an user is able to perform equality test on
the receiver’s ciphertext without decryption when the hidden message belongs to that message set. Similar
to the attri
bute based encryption, ABE. In ABE schemes, those ones who match the settled conditions could
get the privilege of decryption. In FET schemes, those ‘messages inside selected set’ can be equality tested.
Combining PKE schemes and filtered equality test, we propose a framework of public key encryption scheme
with filtered equality test, abbreviated as PKE-FET. Then, taking ElGamal for example, we propose a concrete
PKE-FET scheme based on secret sharing and bilinear map. Finally, we prove our proposition with semantic
security in the standard model.
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