scholarly journals Adaptive Security in Broadcast Encryption Systems (with Short Ciphertexts)

2009 ◽  
pp. 171-188 ◽  
Author(s):  
Craig Gentry ◽  
Brent Waters
Keyword(s):  
Broadcast Encryption ◽  
Adaptive Security

Efficient Anonymous Identity-Based Broadcast Encryption without Random Oracles

2014 ◽  
Vol 6 (2) ◽  
pp. 40-51 ◽  
Author(s):  
Xie Li ◽  
Ren Yanli
Keyword(s):  
Prime Order ◽  
Broadcast Encryption ◽  
Broadcast Channel ◽  
Adaptive Security ◽  
Random Oracles ◽  
Constant Size ◽  
Diffie Hellman ◽  
Identity Based ◽  
Bilinear Groups

Broadcast encryption provides a method of secure multi-receiver communications, where a broadcaster can encrypt a message for a set S of users who are listening to a broadcast channel. Most identity-based broadcast encryption (IBBE) schemes are not anonymous, which means the attacker can obtain the identities of all receivers from the ciphertext. In this paper, the authors propose an efficient anonymous IBBE scheme in bilinear groups of prime order, where any attacker cannot get the identities of the receivers from the ciphertext. The scheme has constant size ciphertext and achieves adaptive security based on the asymmetric decisional bilinear Diffie-Hellman Exponent (DBDHE) assumption without random oracles. The proposed scheme improves efficiency and security of anonymous IBBE schemes simultaneously.

scholarly journals Adaptive Security of Broadcast Encryption, Revisited

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Bingxin Zhu ◽  
Puwen Wei ◽  
Mingqiang Wang
Keyword(s):  
General Result ◽  
Real World ◽  
Broadcast Encryption ◽  
Adaptive Security ◽  
Key Generation ◽  
Constant Size ◽  
Real World Setting ◽  
Target User ◽  
Symmetric Key ◽  
Security Notion

We provide a strong security notion for broadcast encryption, called adaptive security in the multichallenge setting (MA-security), where the adversary can adaptively have access to the key generation oracle and the encryption oracle many times (multichallenge). The adversary specially can query for the challenge ciphertexts on different target user sets adaptively, which generalizes the attacks against broadcast encryptions in the real world setting. Our general result shows that the reduction of the adaptive secure broadcast encryption will lose a factor of q in the MA setting, where q is the maximum number of encryption queries. In order to construct tighter MA-secure broadcast encryptions, we investigate Gentry and Water’s transformation and show that their transformation can preserve MA-security at the price of reduction loss on the advantage of the underlying symmetric key encryption. Furthermore, we remove the q-type assumption in Gentry and Water’s semistatically secure broadcast encryption by using Hofheinz-Koch-Striecks techniques. The resulting scheme instantiated in a composite order group is MA-secure with constant-size ciphertext header.

scholarly journals An Attribute-Based Anonymous Broadcast Encryption Scheme with Adaptive Security in the Standard Model

2017 ◽  
Vol 0 (0) ◽  
pp. 0-0 ◽  
Author(s):  
Reyhaneh Rabaninejad ◽  
Mohammad Hassan Ameri ◽  
Mahshid Delavar ◽  
Javad Mohajeri
Keyword(s):  
Standard Model ◽  
Broadcast Encryption ◽  
Adaptive Security ◽  
Encryption Scheme ◽  
The Standard Model

scholarly journals Location-sharing protocol for privacy protection in mobile online social networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Ou Ruan ◽  
Lixiao Zhang ◽  
Yuanyuan Zhang
Keyword(s):  
Social Networks ◽  
Private Information ◽  
Online Social Networks ◽  
Smart Cities ◽  
Location Based Services ◽  
Broadcast Encryption ◽  
Location Sharing ◽  
Identity Privacy ◽  
And Performance ◽  
Network Server

AbstractLocation-based services are becoming more and more popular in mobile online social networks (mOSNs) for smart cities, but users’ privacy also has aroused widespread concern, such as locations, friend sets and other private information. At present, many protocols have been proposed, but these protocols are inefficient and ignore some security risks. In the paper, we present a new location-sharing protocol, which solves two issues by using symmetric/asymmetric encryption properly. We adopt the following methods to reduce the communication and computation costs: only setting up one location server; connecting social network server and location server directly instead of through cellular towers; avoiding broadcast encryption. We introduce dummy identities to protect users’ identity privacy, and prevent location server from inferring users’ activity tracks by updating dummy identities in time. The details of security and performance analysis with related protocols show that our protocol enjoys two advantages: (1) it’s more efficient than related protocols, which greatly reduces the computation and communication costs; (2) it satisfies all security goals; however, most previous protocols only meet some security goals.

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