Distributed Private Key Generator for ID-Based Public Key Infrastructure

New multivariate cryptosystems are introduced. Sequences f(n) of bijective polynomial transformations of bijective multivariate transformations of affine spaces Kn, n = 2, 3, ... , where K is a finite commutative ring with special properties, are used for the constructions of cryptosystems. On axiomatic level, the concept of a family of multivariate maps with invertible decomposition is proposed. Such decomposition is used as private key in a public key infrastructure. Requirements of polynomiality of degree and density allow to estimate the complexity of encryption procedure for a public user. The concepts of stable family and family of increasing order are motivated by studies of discrete logarithm problem in Cremona group. Statement on the existence of families of multivariate maps of polynomial degree and polynomial density with the invertible decomposition is formulated. We observe known explicit constructions of special families of multivariate maps. They correspond to explicit constructions of families of nonlinear algebraic graphs of increasing girth which appeared in Extremal Graph Theory. The families are generated by pseudorandom walks on graphs. This fact ensures the existence of invertible decomposition; a certain girth property guarantees the increase of order for the family of multivariate maps, good expansion properties of families of graphs lead to good mixing properties of graph based private key algorithms. We describe the general schemes of cryptographic applications of such families (public key infrastructure, symbolic Diffie—Hellman protocol, functional versions of El Gamal algorithm).

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Dynamic Public Key Certificates with Forward Secrecy

Electronics ◽

10.3390/electronics10162009 ◽

2021 ◽

Vol 10 (16) ◽

pp. 2009

Author(s):

Hung-Yu Chien

Keyword(s):

Public Key Infrastructure ◽

Public Key ◽

Practical Reasons ◽

Forward Secrecy ◽

The Public ◽

Private Key ◽

Security Properties ◽

The Subject ◽

Key Exposure ◽

Chameleon Hash

Conventionally, public key certificates bind one subject with one static public key so that the subject can facilitate the services of the public key infrastructure (PKI). In PKI, certificates need to be renewed (or revoked) for several practical reasons, including certificate expiration, private key breaches, condition changes, and possible risk reduction. The certificate renewal process is very costly, especially for those environments where online authorities are not available or the connection is not reliable. A dynamic public key certificate (DPKC) facilitates the dynamic changeover of the current public–private key pairs without renewing the certificate authority (CA). This paper extends the previous study in several aspects: (1) we formally define the DPKC; (2) we formally define the security properties; (3) we propose another implementation of the Krawczyk–Rabin chameleon-hash-based DPKC; (4) we propose two variants of DPKC, using the Ateniese–Medeiros key-exposure-free chameleon hash; (5) we detail two application scenarios.

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An Efficient Identity Based Encryption in Cloud Computing with Outsourced Revocation

International Journal of Scientific Research in Computer Science Engineering and Information Technology ◽

10.32628/cseit20668 ◽

2020 ◽

pp. 72-82

Author(s):

U. Vijay Sankar ◽

M. Pavithra ◽

R Suganya

Keyword(s):

Cloud Computing ◽

Cloud Service ◽

Public Key Infrastructure ◽

Third Party ◽

Public Key ◽

Public Key Encryption ◽

Private Key ◽

Identity Based Encryption ◽

Identity Based ◽

Key Update

Identity-Based Encryption (IBE) which simplifies the public key and certificate management at Public Key Infrastructure (PKI) is an important alternative to public key encryption. However, one of the main efficiency drawbacks of IBE is the overhead computation at Private Key Generator (PKG) during user revocation. Efficient revocation has been well studied in traditional PKI setting, but the cumbersome management of certificates is precisely the burden that IBE strives to alleviate [2]. It aiming at tackling the critical issue of identity revocation, we introduce outsourcing computation into IBE for the first time and propose a revocable IBE scheme in the server-aided setting. Our scheme offloads most of the key generation related operations during key-issuing and key-update processes to a Key Update Cloud Service Provider, leaving only a constant number of simple operations for PKG and users to perform locally [3]. This goal is achieved by utilizing a novel collusion-resistant technique: we employ a hybrid private key for each user, in which an AND gate is involved to connect and bound the identity component and the time component [4]. Furthermore, we propose another construction which is provable secure under the recently formulized Refereed Delegation of Computation model. Finally, we provide extensive experimental results to demonstrate the efficiency of our proposed construction. In public key encryption every user must have a pair of keys, public key and private key, for encrypting and decrypting messages. An Identity-based encryption (IBE) eliminates the need for a Public Key Infrastructure (PKI). IBE uses the human intelligible identities (e.g., unique name, email address, IP address, etc) as public keys [5]. The sender using IBE encrypts message with the receivers’ identity rather than looking for receivers’ public key and corresponding certificate. Accordingly, receiver decrypts ciphertext using private key associated with the corresponding identity [6]. The private keys of users are obtained from a trusted third party called as Private Key Generator (PKG). The motivation of this paper is to study and review an efficient and secure Identity based encryption scheme with outsourced revocation for cloud computing [7].

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Secured Data Transmission in VANET using Vehicular Digital Hash Gen Model

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.f1192.0886s19 ◽

2019 ◽

Vol 8 (6S) ◽

pp. 1008-1011

Keyword(s):

Data Transmission ◽

Public Key Infrastructure ◽

Public Key ◽

The Public ◽

Certificate Revocation ◽

Private Key ◽

Secured Data ◽

Basic Level

Vehicular adhoc structures (VANETs) handle the Public Key Infrastructure (PKI) and Certificate Revocation Lists (CRLs) for their security. In any PKI structure, the check of a got message is performed by checking if the check of the sender is joined into the current CRL, Verifying the reliability of the certification and standard for the sender. In this paper, it has been propose a Vehicular Digital Hash Gen show up (VDHG) for VANETs, which replaces the dull CRL checking process by a profitable revoking checking process. The renouncing check process in VDHG uses a Private Key Infrastructure (PKI), where the key used in finding the VDHG is shared particularly between On-Board Units (OBUs). In like manner, VDHG uses a novel probabilistic key stream, which extras with OBUs to trade and revive an issue key. VDHG can on a very basic level lessen the data torment in light of the message declaration deferral pulled back and the standard assistance structures using CRL.

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