Identity-Based Forward Secure Threshold Signature Scheme Based on Mediated Rsa

A novel ID-based proxy-protected signature scheme based on identity information is presented in this paper. We review the concept ID-Based signature introduced by Shamir, define the security notion of an ID-Based signature. We also improve the Shamir’s ID-Based signature and prove its security under the proposed security notion. From the improved Shamir’s ID-Based signature scheme we construct an ID-Based proxy signature scheme, the security is based on the underlying ID-based signature scheme. Our scheme is efficient and easy to implement. The scheme simplifies the public key as the user’s id and can be easily applied to all the RSA-type cryptosystems.

Post-quantum secure identity-based signature achieving forward secrecy

To maintain security, encryption techniques are used so that the confidentiality of the data is guaranteed. One of the encryption algorithms that is often used is the RSA (Rivest Shamir Adleman) algorithm. On this occasion the author is interested in studying the sql server database security application. In this study, the RSA (Rivest Shamir Adleman) algorithm is used to protect the PKH (Family Hope Program) database. The system will generate public keys and private keys. To secure the PKH database is encrypted with a public key. All data will be encrypted, while the private key will decrypt or restore the original state with the RSA algorithm. The application of the RSA cryptographic algorithm is a good solution for the sql server database security system that will be used to secure the PKH database. To ensure the confidentiality of PKH data stored in the database, by using the RSA algorithm into the system, the data is stored in the database so that the contents of the data cannot be understood by other parties.

Recently, Tseng et al. proposed a new notion for identity-based signature (IBS) scheme to resist ephemeral secret leakage (ESL) attacks, called leakage-free identity-based signature (leakage-free IBS), and devised the first secure leakage-free IBS scheme. However, they only considered the situation of the leakage of ephemeral secrets used for generating the signatures. Notice that the private key extraction procedure is probabilistic as well in their scheme, that is, there are ephemeral secrets used by the key generation center to generate the signers’ private keys. It is practical to consider that if the adversary comprises these ephemeral secrets, then he can reveal the master key of the system. Therefore, it is desired to introduce a new security notion for the leakage-free IBS schemes to consider the ESL attacks on both private key extraction and signing procedures. In this paper, we present such security notion. Moreover, we propose two IBS schemes that are proved to be secure under the new security notion.

In this paper, we first propose an efficient provably secure identity-based signature (IBS) scheme based on bilinear pairings, then propose an efficient identity-based blind signature (IBBS) scheme based on our IBS scheme. Assuming the intractability of the Computational Diffie-Hellman Problem, our IBS scheme is unforgeable under adaptive chosen-message and ID attack. Efficiency analyses show that our schemes can offer advantages in runtime over the schemes available. Furthermore, we show that, contrary to the authors claimed, Zhang and Kim’s scheme in ACISP 2003 is one-more forgeable, if the ROS-problem is solvable.

One important property of group signatures is forward-security, which prevents an attacker in possession of a group signing key to forge signatures produced in the past. In case of exposure of one group member’s signing key, group signatures lacking forward-security need to invalidate all group public and secret keys (by re-initializing the whole system) but also invalidate all previously issued group signatures. Most of the existing forward-secure group signatures (FS-GS) are built from number-theoretic security assumptions which are vulnerable to quantum computers. The only post-quantum secure FS-GS scheme is built from lattices by Ling et al. (PQCrypto 19) in the random oracle model, following the classical framework of encrypt-then-prove, thus using non-interactive zero-knowledge (NIZK) proofs. In this work, we achieve the first FS-GS from lattices in the standard model. Our starting point is the group signature of Katsumada and Yamada (Eurocrypt 19) which replaces NIZK by attribute-based signatures (ABS), thus removing the need for random oracles. We first modify the underlying ABS of Tsabary (TCC 17) to equip it with forward-security property. We then prove that by plugging it back in the group signature framework of Katsumada and Yamada (Eurocrypt 19), we can design a FS-GS scheme secure in the standard model with public key and signature size constant in the number of users. Our constant size is achieved by relying on complexity leveraging, which further implies relying on the subexponential hardness of the Short Integers Solution (SIS) assumption.

Galindo and Garcia introduced a light-wight identity-based signature (IBS) based on Schnorr signature in AFRICACRYPT 2009. Despite the simple construction and the ef-ficiency of Galindo-Garcia IBS, to the best of our knowledge, their followers do not appear except the IBS scheme by Fukumitsu and Hasegawa in CANDAR'17. Although their IBS achieves the tight security, the efficiency is worse than Galindo-Garcia IBS. Their result suggests that Galindo-Garcia IBS utilizes some special properties of Schnorr signature, and we have to deeply observe the structures of both Galindo-Garcia IBS and Schnorr signature to construct their followers. In this paper, we aim to generalize Galindo-Garcia IBS and to search necessary properties of building cryptographic primitives. As a result, we introduce a generic construction of an IBS from a sigma protocol, and find necessary properties to prove the security of the resulting IBS.

Internet Protocol (IP) address management is an increasingly growing concern at Sandia National Laboratories (SNL) and the networking community as a whole. The current state of the available IP addresses indicates that they are nearly exhausted. Currently SNL doesn't have the justification to obtain more IP address space from Internet Assigned Numbers Authority (IANA). There must exist a local entity to manage and allocate IP assignments efficiently. Ongoing efforts at Sandia have been in the form of a multifunctional database application notably known as Network Information System (NWIS). NWIS is a database responsible for a multitude of network administrative services including IP address management. This study will explore the feasibility of augmenting NWIS's IP management capabilities utilizing open source tools. Modifications of existing capabilities to better allocate available IP address space are studied.

A Forward Secure Threshold Signature Scheme from Bilinear Pairing

Comment on “An efficient identity-based signature scheme with provable security”

Secure the communication over network is an important task. Security of Vehicular Ad hoc Networks (VANET) is prime concern due to the numbers of attacker’s existence. We can protect information by using different cryptography methods. The Rivest–Shamir–Adleman (RSA) is one of the asymmetric key cryptography systems to protect information. In asymmetric key cryptography system from the generated key pair, one key is used for information to encrypt and the another key is used for information to decrypt. In RSA, the value of n is computed through the multiplication of two prime numbers p and q. If the factors of n can be found by the intruder using brute force attack, therefore, the security level will reduce. In this paper, we proposed a modified RSA algorithm called MRSA with three prime numbers j, k, and l for VANETs to increase the level of security in vehicular communication. RSA algorithm is with one more prime number, i.e., three prime numbers are used rather than two prime numbers, for increasing the brute force attack time. The lifetime of a message in VANETs may be less. Therefore, MRSA may provide us better result by enhancing the level of security with small key size. The experimental results and analyses are shown for both the RSA and MRSA cryptography algorithms.

One of the important issues in Mobile Ad Hoc NETworks (MANETs) is assignment of Internet Protocol (IP) addresses to nodes. Several address assignment schemes are discussed in Autoconf working group in Internet Engineering Task Force (IETF). These schemes are based on autonomously decentralized manner, and it may cause duplication of assigned IP addresses. The duplication of IP addresses disturbs route computation because routing protocols assume uniqueness of IP addresses. Therefore, a Duplicate Address Detection (DAD) scheme is needed. Weak DAD uses a unique key for the detection of duplicated IP addresses. This key is advertised together with the IP address in control messages for routing. By finding the conflict of keys, duplicated IP addresses are detected. This scheme can use a simple rule, but it requires large overhead because key size should be large enough to satisfy the uniqueness. In this paper, we propose a partial-key DAD for the reduction of control overhead. In the partial-key DAD, the original key is divided into several partial keys, and one of them is attached to each control message. We evaluate the performance of the partial-key DAD, and show that it can reduce the control overhead although the resolution time of duplicated IP addresses increases slightly.

Recently, the notion of the key-insulated public- key system has been suggested to protect the security of users' private keys. A general idea of this system is changing the user's private key along with the time, but the user's public key remains unchanged. In this paper, we propose a new identity (ID)-based key-insulated signature scheme from bilinear pairings. As compared with the recently proposed ID-based key-insulated signature schemes, our proposed scheme has better performance in the batch verifying phase. For security analysis, our scheme is a provably secure key-insulated signature scheme in the random oracle model and under the computational Diffie-Hellman assumption. Meanwhile, to demonstrate the additional advantage of a key-insulated signature, we present a novel application based on the proposed scheme, called full delegation ID-based proxy signature scheme with time restriction. To our best knowledge, no such a proxy signature scheme is proposed until now.

In 1984, Shamir introduced the concept of an identity-based encryption. In this system, each user needs to visit a private key generation (PKG) and identify him- self before joining a communication network. Once a user is accepted, the PKG will provide him with a secret key. In this way, if a user wants to communicate with others, he only needs to know the ―identity‖ of his communication partner and the public key of the PKG. There is no public file required in this system. However, Shamir did not succeed in constructing an identity based encryption, but only in constructing an identity-based signature (IBS) scheme. In this paper, we propose an identity based encryption (IBE) based on the factorization problem (IFP) and double discrete logarithm problem (DDLP) and we consider the security against a conspiracy of some entities in the proposed system and show the possibility of establishing a more secure system.

RSA [1] is one of the mostly used cryptosystem in securing data and information. Though, it has been recently discovered that RSA has some weaknesses and in advance technology, RSA is believed to be inefficient especially when it comes to decryption. Thus, a new algorithm called Multi prime RSA, an extended version of the standard RSA is studied. Then, a modification is made to the Multi prime RSA where another keys is shared secretly between the receiver and the sender to increase the securerity. As in RSA, the methodology used for modified Multi-prime RSA also consists of three phases; 1. Key Generation in which the secret and public keys are generated and published. In this phase, the secrecy is improved by adding more prime numbers and addition of secret keys. 2. Encryption of the message using the public and secret keys given. 3. Decryption of the secret message using the secret key generated. For the decryption phase, a method called Chinese Remainder Theorem is used which helps to fasten the computation. Since Multi prime RSA use more than two prime numbers, the algorithm is more efficient and secure when compared to the standard RSA. Furthermore, in modified Multi prime RSA another secret key is introduced to increase the obstacle to the attacker. Therefore, it is strongly believed that this new algorithm is better and can be an alternative to the RSA.