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

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.

Cryptography ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 33 ◽  
Author(s):  
Ziyuan Hu ◽  
Shengli Liu ◽  
Kefei Chen ◽  
Joseph Liu

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.


2013 ◽  
Vol 765-767 ◽  
pp. 1726-1729
Author(s):  
Yan Bing Liu ◽  
Wen Jing Ren

Security and privacy is always the most important issues by the public in the Internet of Things. The core problems are associated with the diversifying of the Internet towards an Internet of things, and the different requirements to the security level for application. Therefore, this paper is to put forward an authentication model and protocol to cope with the problem. The protocol is adopted with attribute-based encryption to replace the traditional identity-based encryption (IBE), and then make formalization analysis to the security of the protocol by using BAN logic.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Jingang Liu ◽  
Yongge Wang ◽  
Zongxiang Yi ◽  
Zhiqiang Lin

Security challenges brought about by the upcoming 5G era should be taken seriously. Code-based cryptography leverages difficult problems in coding theory and is one of the main techniques enabling cryptographic primitives in the postquantum scenario. In this work, we propose the first efficient secure scheme based on polar codes (i.e., polarRLCE) which is inspired by the RLCE scheme, a candidate for the NIST postquantum cryptography standardization in the first round. In addition to avoiding some weaknesses of the RLCE scheme, we show that, with the proper choice of parameters, using polar codes, it is possible to design an encryption scheme to achieve the intended security level while retaining a reasonably small public key size. In addition, we also present a KEM version of the polarRLCE scheme that can attain a negligible decryption failure rate within the corresponding security parameters. It is shown that our proposal enjoys an apparent advantage to decrease the public key size, especially on the high-security level.


Cryptography ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 21
Author(s):  
Koki Jimbo ◽  
Satoshi Iriyama ◽  
Massimo Regoli

A new public key agreement (PKA) algorithm, called the strongly-asymmetric algorithm (SAA-5), was introduced by Accardi et al. The main differences from the usual PKA algorithms are that Bob has some independent public keys and Alice produces her public key by using some part of the public keys from Bob. Then, the preparation and calculation processes are essentially asymmetric. This algorithms has several free parameters more than the usual symmetric PKA algorithms and the velocity of calculation is largely dependent on the parameters chosen; however, the performance of it has not yet been tested. The purpose of our study was to discuss efficient parameters to share the key with high speeds in SAA-5 and to optimize SAA-5 in terms of calculation speed. To find efficient parameters of SAA-5, we compared the calculation speed with Diffie–Hellman (D-H) while varying values of some parameters under the circumstance where the length of the secret shared key (SSK) was fixed. For optimization, we discuss a more general framework of SAA-5 to find more efficient operations. By fixing the parameters of the framework properly, a new PKA algorithm with the same security level as SAA-5 was produced. The result shows that the calculation speed of the proposed PKA algorithm is faster than D-H, especially for large key lengths. The calculation speed of the proposed PKA algorithm increases linearly as the SSK length increases, whereas D-H increases exponentially.


Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 913
Author(s):  
Lifeng Guo ◽  
Jing Wang ◽  
Wei-Chuen Yau

Security is a main concern for the Internet of Things (IoT) infrastructure as large volumes of data are collected and processed in the systems. Due to the limited resources of interconnected sensors and devices in the IoT systems, efficiency is one of the key considerations when deploying security solutions (e.g., symmetric/asymmetric encryption, authentication, etc.) in IoT. In this paper, we present an efficient Hierarchical Identity-Based Encryption (HIBE) system with short parameters for protecting data confidentiality in distributed IoT infrastructure. Our proposed HIBE system has the public parameters, private key, and ciphertext, each consisting of a constant number of group elements. We prove the full security of the HIBE system in the standard model using the dual system encryption technique. We also implement the proposed scheme and compare the performance with the original Lewko–Waters HIBE. To the best of our knowledge, our construction is the first HIBE system that achieves both full security in the standard model and short parameters in terms of the public parameters, private key, and ciphertext.


Author(s):  
Kannan Balasubramanian ◽  
M. Rajakani

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.


Author(s):  
Kannan Balasubramanian ◽  
M. Rajakani

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.


2014 ◽  
Vol 687-691 ◽  
pp. 2165-2168
Author(s):  
Xue Dong Dong ◽  
Hui Min Lu

Certificateless-based signature can eliminate the need of certificates in the Public Key Infrastructure and solve the inherent key escrow problem in the identity-based cryptography. In 2012 Zhang et al. [J. Zhang and J. Mao, An efficient RSA-based certificateless signature scheme, Journal of Systems and Software, vol. 85, pp. 638-642, 2012] proposed the first certificateless signature scheme based on RSA operations and showed that their scheme is provably secure in the random oracle model. However, He et al. [D. He, M.Khan, and S. Wu, On the security of a RSA-based certificateless signature scheme, International Journal of Network Security, vol.16, no.1, pp.78-80, 2014] recently showed that Zhang et al.'s scheme is insecure against a type I adversary who can replace users' public keys. In this paper, we propose an improved version based on RSA which not only keeps the original security properties of the signature, but also is secure against a type I adversary.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Caixue Zhou

Certificate-based cryptosystem can not only resolve the private key escrow problem inherent in the identity-based cryptosystem but also reduce the cost of public key certificate management in the public key infrastructure-(PKI-) based cryptosystem. Provable data possession (PDP) can ensure the integrity of users’ data stored in the cloud at a very high probability. By combining these two concepts, we propose a certificate-based PDP scheme. We prove that our scheme is secure in the standard model assuming that the Squ-CDH problem is hard. Based on the index logic table, our scheme can be extended to support dynamic operations easily. Efficiency analysis shows that our scheme has high efficiency.


2020 ◽  
Author(s):  
Hui Cui ◽  
Russell Paulet ◽  
Surya Nepal ◽  
Xun Yi ◽  
Butrus Mbimbi

Abstract Biometric information is unique to a human, so it would be desirable to use the biometric characteristic as the private key in a cryptographic system to protect data security and privacy. In this paper, we introduce a notion called two-factor decryption (TFD). Informally speaking, a TFD scheme is a variant of the public-key encryption (PKE) scheme. In a TFD scheme, messages are encrypted under public keys as that in a standard PKE scheme, but both private keys (i.e. the first factor) and biometric inputs (i.e. the second factor) are required to decrypt the ciphertexts and obtain the underlying plaintexts. We first describe a framework of TFD, and then define a formal security model for TFD. Thereafter, we present a generic construction on TFD based on the cryptographic primitives of linear sketch and functional encryption (FE) with certain properties and analyse its security. In addition, we give instantiations of TFD by applying concrete FE schemes into the generic construction and show their applications.


Sign in / Sign up

Export Citation Format

Share Document