scholarly journals Revocable Identity-Based Encryption and Server-Aided Revocable IBE from the Computational Diffie-Hellman Assumption

Cryptography ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 33 ◽  
Author(s):  
Ziyuan Hu ◽  
Shengli Liu ◽  
Kefei Chen ◽  
Joseph Liu
Keyword(s):  
Key Management ◽  
Time Slot ◽  
Complete Binary Tree ◽  
The Past ◽  
Identity Based Encryption ◽  
Diffie Hellman ◽  
Public Keys ◽  
The Standard Model ◽  
Cdh Assumption ◽  
Identity Based

An Identity-based encryption (IBE) simplifies key management by taking users’ identities as public keys. However, how to dynamically revoke users in an IBE scheme is not a trivial problem. To solve this problem, IBE scheme with revocation (namely revocable IBE scheme) has been proposed. Apart from those lattice-based IBE, most of the existing schemes are based on decisional assumptions over pairing-groups. In this paper, we propose a revocable IBE scheme based on a weaker assumption, namely Computational Diffie-Hellman (CDH) assumption over non-pairing groups. Our revocable IBE scheme is inspired by the IBE scheme proposed by Döttling and Garg in Crypto2017. Like Döttling and Garg’s IBE scheme, the key authority maintains a complete binary tree where every user is assigned to a leaf node. To adapt such an IBE scheme to a revocable IBE, we update the nodes along the paths of the revoked users in each time slot. Upon this updating, all revoked users are forced to be equipped with new encryption keys but without decryption keys, thus they are unable to perform decryption any more. We prove that our revocable IBE is adaptive IND-ID-CPA secure in the standard model. Our scheme serves as the first revocable IBE scheme from the CDH assumption. Moreover, we extend our scheme to support Decryption Key Exposure Resistance (DKER) and also propose a server-aided revocable IBE to decrease the decryption workload of the receiver. In our schemes, the size of updating key in each time slot is only related to the number of newly revoked users in the past time slot.

scholarly journals Adaptively Secure Efficient (H)IBE over Ideal Lattice with Short Parameters

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1247
Author(s):  
Yuan Zhang ◽  
Yuan Liu ◽  
Yurong Guo ◽  
Shihui Zheng ◽  
Licheng Wang
Keyword(s):  
Computational Cost ◽  
Security Level ◽  
Chosen Plaintext Attack ◽  
Cryptographic Primitives ◽  
The Public ◽  
The Past ◽  
Ideal Lattices ◽  
Public Keys ◽  
The Standard Model ◽  
Identity Based

Identity-based encryption (IBE), and its hierarchical extension (HIBE), are interesting cryptographic primitives that aim at the implicit authentication on the users’ public keys by using users’ identities directly. During the past several decades, numerous elegant pairing-based (H)IBE schemes were proposed. However, most pairing-related security assumptions suffer from known quantum algorithmic attacks. Therefore, the construction of lattice-based (H)IBE became one of the hot directions in recent years. In the setting of most existing lattice-based (H)IBE schemes, each bit of a user’s identity is always associated with a parameter matrix. This always leads to drastic but unfavorable increases in the sizes of the system public parameters. To overcome this issue, we propose a flexible trade-off mechanism between the size of the public parameters and the involved computational cost using the blocking technique. More specifically, we divide an identity into l′ segments and associate each segment with a matrix, while increasing the lattice modulo slightly for maintaining the same security level. As a result, for the setting of 160-bit identities, we show that the size of the public parameters can be reduced by almost 89.7% (resp. 93.8%) while increasing the computational cost by merely 5.2% (resp. 12.25%) when l′ is a set of 16 (resp. 8). Finally, our IBE scheme is extended to an HIBE scheme, and both of them are proved to achieve the indistinguishability of ciphertexts against adaptively chosen identity and chosen plaintext attack (IND-ID-CPA) in the standard model, assuming that the well-known ring learning with error (RLWE) problem over the involved ideal lattices is intractable, even in the post-quantum era.

Security of Identity-Based Encryption Algorithms

2018 ◽  
pp. 4975-4984
Author(s):  
Kannan Balasubramanian ◽  
M. Rajakani
Keyword(s):  
Key Management ◽  
Public Key ◽  
The Public ◽  
Private Key ◽  
Identity Based Encryption ◽  
Public Keys ◽  
Identity Based ◽  
Encryption Algorithms ◽  
Encrypted Communication ◽  
E Mail

The concept of Identity Based Cryptography introduced the idea of using arbitrary strings such as e-mail addresses and IP Addresses to form public keys with the corresponding private keys being created by the Trusted Authority(TA) who is in possession of a system-wide master secret. Then a party, Alice who wants to send encrypted communication to Bob need only Bob's identifier and the system-wide public parameters. Thus the receiver is able to choose and manipulate the public key of the intended recipient which has a number of advantages. While IBC removes the problem of trust in the public key, it introduces trust in the TA. As the TA uses the system-wide master secret to compute private keys for users in the system, it can effectively recompute a private key for any arbitrary string without having to archive private keys. This greatly simplifies key management as the TA simply needs to protect its master secret.

Security of Identity-Based Encryption Algorithms

2019 ◽  
pp. 312-325
Author(s):  
Kannan Balasubramanian ◽  
M. Rajakani
Keyword(s):  
Key Management ◽  
Public Key ◽  
The Public ◽  
Private Key ◽  
Identity Based Encryption ◽  
Public Keys ◽  
Identity Based ◽  
Encryption Algorithms ◽  
Encrypted Communication ◽  
E Mail

The concept of identity-based cryptography introduced the idea of using arbitrary strings such as e-mail addresses and IP addresses to form public keys with the corresponding private keys being created by the trusted authority (TA) who is in possession of a systemwide master secret. Then a party, Alice, who wants to send encrypted communication to Bob need only Bob's identifier and the systemwide public parameters. Thus, the receiver is able to choose and manipulate the public key of the intended recipient which has a number of advantages. While IBC removes the problem of trust in the public key, it introduces trust in the TA. As the TA uses the systemwide master secret to compute private keys for users in the system, it can effectively recompute a private key for any arbitrary string without having to archive private keys. This greatly simplifies key management as the TA simply needs to protect its master secret.

New Constructions of Hierarchical Identity-Based Signature in the Standard Model

2011 ◽  
Vol 474-476 ◽  
pp. 1356-1361
Author(s):  
Qing Wu ◽  
Su Xia Sun
Keyword(s):  
Standard Model ◽  
Provable Security ◽  
Security Model ◽  
Private Key ◽  
Random Oracles ◽  
Diffie Hellman ◽  
The Standard Model ◽  
Cdh Assumption ◽  
Identity Based ◽  
Provably Secure

In this paper, a new construct of hierarchical identity-based signature(HIBS) scheme is proposed at first. It has many advantages over those available, such as fully secure without using random oracles, efficient signing algorithm. Additionally, it is provably secure under the computational Diffie-Hellman(CDH) assumption. This assumption is more natural than many of the hardness assumptions recently introduced to HIBS in the standard model. However, the length of its private key and signature increases as the hierarchy depth expands. Then a modified scheme is presented. The signature of modified scheme consists of three group elements and the private keys size shrinks as the identity depth increases. Under the h-CDH assumption, it is provable security in full security model without using random oracles.

Fuzzy Error-Tolerance Biometric Identity-Based Signature in the Standard Model

2011 ◽  
Vol 148-149 ◽  
pp. 474-477
Author(s):  
Le You Zhang ◽  
Qing Wu ◽  
Yu Pu Hu
Keyword(s):  
Standard Model ◽  
Error Tolerance ◽  
Signature Scheme ◽  
Natural Assumption ◽  
Diffie Hellman ◽  
The Standard Model ◽  
Cdh Assumption ◽  
Identity Based ◽  
Biometric Measurements

Biometric measurements are noisy and the existing techniques cannot be used directly to construct biometric-based scheme. Hence an error-tolerance property(Fuzzy) can be used to solve this problem. In this paper, a new biometric identity based signature scheme is proposed with the error-tolerance property. Our scheme is constructed in the standard model and achieves the selective identity security. In addition, the security of our scheme is reduced to a natural assumption-Computation Diffie-Hellman(CDH) assumption instead of other strong assumptions.

Fuzzy Biometric Identity-Based Signature in the Standard Model

2010 ◽  
Vol 44-47 ◽  
pp. 3350-3354 ◽  
Author(s):  
Le You Zhang ◽  
Qing Wu ◽  
Yu Pu Hu
Keyword(s):  
Standard Model ◽  
Error Tolerance ◽  
Signature Scheme ◽  
Property A ◽  
Diffie Hellman ◽  
The Standard Model ◽  
Cdh Assumption ◽  
Identity Based ◽  
Biometric Measurements

Using a biometric as an identity has the advantage that identities are unique if the underlying biometric is of a good quality, such as fingerprints, faces, irises, etc. However, biometric measurements are noisy and the existing identity-based systems cannot be used directly to construct this scheme. The error-tolerance property(Fuzzy) can be used to solve this problem. Based on the error-tolerance property, a new biometric identity based signature scheme is proposed. Our scheme is constructed in the standard model and achieves a strong security-full security. In addition, the security of our scheme is reduced to a generalized assumption-Computation Diffie-Hellman(CDH) assumption instead of other strong assumptions.

Fuzzy Techniques in Biometric IBE without Random Oracles

2011 ◽  
Vol 148-149 ◽  
pp. 112-115
Author(s):  
Qing Wu
Keyword(s):  
Error Tolerance ◽  
Property A ◽  
Private Key ◽  
Random Oracles ◽  
Identity Based Encryption ◽  
Diffie Hellman ◽  
The Standard Model ◽  
Identity Based ◽  
Biometric Measurements ◽  
Fuzzy Techniques

Using a biometric as an identity has the advantage that identities are unique if the underlying biometric is of a good quality, such as fingerprints, faces, irises. Since biometric measurements are noisy, the existing identity-based encryption systems cannot be used directly to construct IBE scheme. The error-tolerance property of Fuzzy-IBE allows for a private key to decrypt a ciphertext encrypted with a slightly different measurement of the same biometric. Based on this property, a new biometric identity based encryption scheme is proposed. Our scheme is constructed in the standard model and achieves a selective identity security. In addition, the security of our scheme is reduced to decision bilinear Diffie-Hellman(BDH) assumption instead of other strong assumptions.

scholarly journals A Pairing-Free Identity-Based Identification Scheme with Tight Security Using Modified-Schnorr Signatures

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1330
Author(s):  
Jason Chia ◽  
Ji-Jian Chin ◽  
Sook-Chin Yip
Keyword(s):  
Key Management ◽  
Discrete Logarithm ◽  
Probability Bounds ◽  
Diffie Hellman ◽  
Identity Based ◽  
Symmetric Key ◽  
Security Guarantees ◽  
Lightweight Authentication ◽  
Tight Security ◽  
Schnorr Signatures

The security of cryptographic schemes is proven secure by reducing an attacker which breaks the scheme to an algorithm that could be used to solve the underlying hard assumption (e.g., Discrete Logarithm, Decisional Diffie–Hellman). The reduction is considered tight if it results in approximately similar probability bounds to that of solving the underlying hard assumption. Tight security is desirable as it improves security guarantees and allows the use of shorter parameters without the risk of compromising security. In this work, we propose an identity-based identification (IBI) scheme with tight security based on a variant of the Schnorr signature scheme known as TNC signatures. The proposed IBI scheme enjoys shorter parameters and key sizes as compared to existing IBI schemes without increasing the number of operations required for its identification protocol. Our scheme is suitable to be used for lightweight authentication in resource-constrained Wireless Sensor Networks (WSNs) as it utilizes the lowest amount of bandwidth when compared to other state-of-the-art symmetric key lightweight authentication schemes. Although it is costlier than its symmetric key counterparts in terms of operational costs due to its asymmetric key nature, it enjoys other benefits such as decentralized authentication and scalable key management. As a proof of concept to substantiate our claims, we perform an implementation of our scheme to demonstrate its speed and memory usage when it runs on both high and low-end devices.

Research on Identity-Based Encryption Scheme for Grid Computing System

2014 ◽  
Vol 543-547 ◽  
pp. 3156-3159
Author(s):  
Qing Hai Bai ◽  
Ying Zheng ◽  
Qing Hu Wang ◽  
Guo Li Wei ◽  
Hai Chun Zhao ◽  
...  
Keyword(s):  
Grid Computing ◽  
Data Transmission ◽  
Computing System ◽  
Grid Service ◽  
Encryption Scheme ◽  
Grid System ◽  
Identity Based Encryption ◽  
Diffie Hellman ◽  
Long Run ◽  
Identity Based

Grid system has secure requirements of confidential communication, data integrity and non-repudiation. According to the secure requirements for Grid service, the paper proposed an identity-based encryption scheme for Grid, which can solve a series of problem: the privacy of data transmission, validation of integrity of data, key update after long run time and non-repudiation. The scheme is constructed by bilinear paring on elliptic cures and its security can be reduced to the computational Bilinear Diffie-Hellman assumption. Finally, the authors analyses the security and efficiency of this scheme.

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