Mitigating Server Breaches in Password-Based Authentication: Secure and Efficient Solutions

Nowadays, Smooth Projective Hash Functions (SPHFs) play an important role in constructing cryptographic tools such as secure Password-based Authenticated Key Exchange (PAKE) protocol in the standard model, oblivious transfer, and zero-knowledge proofs. Specifically, in this article, we focus on constructing PAKE protocol; that is, a kind of key exchange protocol which needs only a low entropy password to produce a cryptographically strong shared session key. In spite of relatively good progress of SPHFs in applications, it seems there has been little effort to build them upon quantum-resistant assumptions such as lattice-based cryptography and code-based cryptography to make them secure against quantum computer attacks. More precisely, there are two proposals based on lattice assumptions that utilize the SPHFs to construct PAKE secured in standard model. Considering quantum-resistant assumptions is less than straightforward and needs some relaxations. In this article, we introduce two new Approximate SPHF (ASPHFs) from error-correcting codes. Upon designing ASPHF, we can construct two efficient PAKE protocols. The security of our protocols could be proved based on the hardness of bounded decoding (BD) problem and learning with parity (LPN) problem in the standard model.

There have been many proposals in recent years for password-authenticated key exchange protocols.Man y of these have been shown to be insecure, and the only ones that seemed likely to be proven secure (against active adversaries who may attempt to perform off-line dictionary attacks against the password) were based on the Diffie-Hellman problem. In fact, some protocols based on Diffie-Hellman have been recently proven secure in the random-oracle model. We examine how to design a provably-secure password-authenticated key exchange protocol based on RSA.We first look at the OKE and protected-OKE protocols (both RSA-based) and show that they are insecure.Then we show how to modify the OKE protocol to obtain a password-authenticated key exchange protocol that can be proven secure (in the random oracle model). The resulting protocol is very practical; in fact the basic protocol requires about the same amount of computation as the Diffie-Hellman-based protocols or the well-known ssh protocol.

A password-authenticated key exchange (PAKE) protocol allows two entities sharing a password to perform mutual authentication and establish a session key. Benefiting from the use of a low-entropy human-memorable password, PAKE avoids the use of PKI in the authentication process, making it more flexible and cheaper. However, with the development of quantum computing, protocols based on classical assumptions will no longer be secure, so designing a PAKE protocol capable of resisting quantum attacks has become an important research direction. In this work, we propose an efficient PAKE protocol using a new error reconciliation mechanism based on the ring learning with errors (RLWE) problem, which is considered to resist quantum attacks. Our protocol is proven security under the Bellare-Pointcheval-Rogaway (BPR) model. The protocol is implemented using the C language, which is highly portable, and is also optimized utilizing the Advanced Vector Extensions 2 (AVX2) instruction set. Compared with the C implementation of Ding’s protocol, our reference C implementation is more than 12x faster, and the efficiency is doubled after AVX2 optimization. Moreover, by choosing the appropriate parameters, the security strength of our scheme is improved and the message size is reduced.

Industrial Internet of Things (IIoT) brings together computers, devices, advanced analytics, and people in industries, such as transportation, oil plant, and power grid that leads to major efficiency and productivity gains for almost any industrial procedures. Due to the interconnection of devices in IIoT, communication security has become a critical issue to address in many emerging industry standards that require the authentication and key exchange procedure to be done to guarantee the authorized machine access (e.g., from users) and secure the data transmission between machines. To overcome the shortcoming (i.e., low entropy) of the memorable password in user authentication, it is rightfully recommended by industry standards (such as IEC-62443 family) to use multifactor authentication (MFA) for higher security levels. Notably, latency is one of the main sources of inefficiency when a device is communicating with other machines on IIoT. To mitigate latency, a smooth projective hash function (SPHF) built from well-studied standard assumptions is used to achieve a lowinteractivity multifactor authenticated key exchange protocol (MFAKE) because SPHF allows each party to prove to the others that he knows the right authentication factor(s). In this article, we are, therefore, motivated to build a new MFAKE named “secure remote multifactor (SRMF)” to achieve the humaninvolved “machine-to-machine” secure communication in IIoT. That is, SRMF leverages multiple user-centric authentication factors (such as password, biometric fingerprints, and PIN), and it can synergistically support multifactor registration (MFR), MFA, and multifactor key exchange (MFKE). Furthermore, to prevent authentication factors stored at the server exposing to attackers, the password-harden service (i.e., Pythia-PRF and USENIX'15) inspires us to develop a multifactor hardening service (MFHS) utilizing an oblivious pseudorandom function (OPRF). The balanced security of the proposed protocol is proved under the model of Bellare-Pointcheval-Rogaway (EUROCRYPTO'00) along with theoretical and experimental evaluations.

Vehicle authentication is an essential component validating the vehicle’s identity and ensuring the integrity of transformed data for intelligent transport vehicles (ITS) in the vehicular ad hoc network (VANET). Easy to deploy and operate privacy-enhancing vehicle authentication mechanisms are the mainstay for the widespread ITS in the VANET. Very recently, VANET security architectures are constituting by IEEE 1609.2 group, NoW project, the SeVeCom project. However, these approaches heavily depend on the consuming public key infrastructure (PKI) and certification authorities (CA). In this work, walking along the research line, we attempt to design authentication protocols with two diverse factors for Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) networks, respectively, without depending on the stumbling block PKI/CA. In addition, a smooth projective hash function (SPHF) (a.k.a., a special case of the designated-verifier zero-knowledge proof system) guarantees any recipient can confirm the authenticity and integrity of the received messages without knowing the authentication factors. Thus, to optimize the communication round, SPHF is used to design a (group) two-factor authenticated key exchange (AKE) with low-interactive communication rounds. The proof-of-concept implementation indicates that the computation and communication overheads introduced by our solution are acceptable in real-world deployments. The security of the proposed approach is validated using Bellare-Pointcheval-Rogaway (BPR) model along with the experimental evaluation and the theoretical analysis.

A secure and efficient AKE scheme for IoT devices using PUF and cancellable biometrics

With the popularity of unmanned aerial vehicles (UAVs), more and more valuable data can be collected by UAVs. In order to balance the data usage and communication cost, the data can be preprocessed in UAVs rather than directly transmitting to the data centre in the edge computing paradigm. Users can obtain information of interest by accessing the data centre remotely by authenticating themselves to the data centre using the most pervasive password authentication method. Unfortunately, the data centre becomes the main attack target because it not only stores the data but also maintains the passwords of all the users. Aiming at protecting the data as well as the password in the UAV‐enabled mobile edge computing environment, the authors combine the advantages of gateway‐oriented password authenticated key exchange (PAKE) protocols and two‐server PAKE protocols and put forward an efficient gateway‐oriented two‐server PAKE protocol. The security of the proposed protocol is given in the random oracle model. The performance comparison shows their proposal has comparable efficiency in computation and communication costs. Their protocol provides better protection to the password without sacrificing efficiency. Consequently, their protocol is more suitable for real applications in UAV‐enabled mobile edge computing environment.

In recent years, many password authenticated key exchange (PAKE) protocols have been proposed. However, many of them have been broken or have no security proof. In this paper, we propose an efficient password authenticated key exchange protocol using bilinear pairings. Compared with previous PAKE protocol using bilinear pairings, our protocol is quite efficient both in communication cost and computational cost. Moreover, this paper proves that the novel protocol is forward secrecy under the Bilinear Diffie-Hellman (BDH) assumption in the random oracle model.KeywordsPAKEbilinear paringBDHforward secrecy

One of the main lines of research in functional encryption (FE) has consisted in studying the security notions for FE and their achievability. This study was initiated by [Boneh et al. – TCC’11, O’Neill – ePrint’10] where it was first shown that for FE the indistinguishability-based (IND) security notion is not sufficient in the sense that there are FE schemes that are provably IND-Secure but concretely insecure. For this reason, researchers investigated the achievability of Simulation-based (SIM) security, a stronger notion of security. Unfortunately, the above-mentioned works and others [e.g., Agrawal et al. – CRYPTO’13] have shown strong impossibility results for SIM-Security. One way to overcome these impossibility results was first suggested in the work of Boneh et al. where it was shown how to construct, in the Random Oracle (RO) model, SIM-Secure FE for restricted functionalities and was asked the generalization to more complex functionalities as a challenging problem in the area. Subsequently, [De Caro et al. – CRYPTO’13] proposed a candidate construction of SIM-Secure FE for all circuits in the RO model assuming the existence of an IND-Secure FE scheme for circuits with RO gates. To our knowledge there are no proposed candidate IND-Secure FE schemes for circuits with RO gates and they seem unlikely to exist. We propose the first constructions of SIM-Secure FE schemes in the RO model that overcome the current impossibility results in different settings. We can do that because we resort to the two following models: Both results also assume the RO model, but not functionalities with RO gates and rely on extractability obfuscation [Boyle et al. – TCC’14] (and other standard primitives) secure only in the standard model.

Indistinguishability under chosen-ciphertext attack (IND-CCA) is now considered the de facto security notion for public-key encryption. However, this sometimes offers a stronger security guarantee than what is needed. In this study, the authors consider a weaker security notion, termed as indistinguishability under plaintext-checking attacks (IND-PCA), in which the adversary has only access to an oracle indicating whether or not a given ciphertext encrypts a given message. After formalising this notion, the authors design a new public-key encryption scheme satisfying it. The new scheme is a variant of the Cramer–Shoup encryption scheme with shorter ciphertexts. Its security is also based on the plain decisional Diffie–Hellman (DDH) assumption. Additionally, the algebraic properties of the new scheme allow proving plaintext knowledge using Groth–Sahai non-interactive zero-knowledge proofs or smooth projective hash functions. Finally, as a concrete application, the authors show that, for many password-based authenticated key exchange (PAKE) schemes in the Bellare–Pointcheval–Rogaway security model, they can safely replace the underlying IND-CCA encryption schemes with their new IND-PCA one. By doing so, they reduce the overall communication complexity of these protocols and obtain the most efficient PAKE schemes to date based on plain DDH.

Cryptographic Primitives that Resist Backdooring and Subversion

We construct a publicly verifiable protocol for proving computational work based on collision-resistant hash functions and a new plausible complexity assumption regarding the existence of hash functions. Our protocol is based on a novel construction of puzzles. Given a sampled P getsr Dn, where $n$ is the security parameter and Dn is the distribution of the puzzles, a corresponding can be generated using N evaluations of the sequential hash function, where N>n is another parameter, while any feasible adversarial strategy for generating valid solutions must take at least as much time as Ω(N) serial evaluations of the hash function after receiving $P$. Thus, valid solutions constitute a proof that Ω(N) parallel time elapsed since p was received. Solutions can be publicly and efficiently verified in time poly(n) ⋅ polylog(N). Applications of these time-lock include noninteractive timestamping of documents (where the distribution over the possible documents corresponds to the puzzle distribution Dn) and universally verifiable CPU benchmarks. Our construction is secure in the standard model under complexity assumptions (collision-resistant hash functions and inherently sequential hash functions), and makes black-box use of the underlying primitives. Consequently, the corresponding construction in the random oracle model is secure unconditionally. Moreover, as it is a public-coin protocol, it can be made non-interactive in the random oracle model using the Fiat-Shamir Heuristic.Our construction makes a novel use of depth-robust directed acyclic graphs---ones whose depth remains large even after removing a constant fraction of vertices---which were previously studied for the purpose of complexity lower-bounds. The construction bypasses a recent lower-bound of Mahmoody, Moran, and Vadhan (CRYPTO '11) for puzzles in the random oracle model, which showed that it is impossible to have puzzles like ours in the random oracle model if the puzzle generator also computes a solution together with the puzzle.

Online/offline identity-based signature (OO-IBS) is a versatile cryptographic tool to provide the message authentication and integrity in mobile devices, since it lightens the computational burden after the signer receiving the message and eliminates the overhead of certificate management. It has several valuable applications, for instance, wireless sensor networks. Identity-based chameleon hash (IB-CH), as an alternative building block to construct OO-IBS, has been explored in numerous literatures. Nevertheless, there still exist two major issues. 1) Nearly all of the previous IB-CH schemes with weak collision-resistance (W-CollRes) are with random oracles, which may lead to security risks in practicality. The only IB-CH scheme in the standard model suffers from the large size of public parameters and inefficient setup process. 2) The only IB-CH scheme without key exposure also relies on random oracles. In this paper, we propose two novel IB-CH schemes in the standard model. The first scheme is adaptive identity, W-CollRes secure and efficient, significantly reducing the computation costs of all algorithms and the size of public parameters compared with the existing scheme in the standard model. The second scheme is the first IB-CH achieving key exposure freeness without random oracles. Both theoretical and experimental analyses demonstrate the good performance of our proposed schemes. Furthermore, we apply our schemes to optimizing the existing generic OO-IBS construction. The optimized generic constructions reduce computational overhead by 50.0% in the online phase and enable the hash value/signature tuple generated in the offline phase to be reusable, respectively.

In smart grid, key exchange protocols play a vital role in providing secure channels to read consumption reports from the smart meters. Thus far, several key exchange schemes have been proposed for the networked smart meters. However, for the first time, quite recently, Sha et al . have presented an interesting two-phase authentication and key agreement scheme that exclusively aims at the isolated smart meters. In their scheme, they have properly addressed the computationally constrained smart meters by offering a lightweight key exchange protocol. Nevertheless, after meticulous observation, we found that their proposed scheme cannot resist the desynchronization attack and cannot provide the perfect forward secrecy. Moreover, there are some other weaknesses in their scheme. As a result, to tackle the existing security challenges, in this paper, by utilization of the extended Chebyshev chaotic maps, we propose an efficient anonymous password-authenticated key exchange protocol that not only is free from the limitations of Sha et al .'s scheme, but also provides the anonymity. The security analysis in the random oracle model and using the widely accepted ProVerif tool besides the computational and communication costs comparison demonstrate that the proposed scheme has reached a proper level of efficiency without sacrificing the desired security properties.

An improved password-authenticated key exchange protocol for VANET