Pre-shared Key Research Articles

An over-the-air key establishment protocol using keyless cryptography

Today, an increasing number of devices wirelessly communicate with each other. However, due to the nature of wireless transmission, the communications are vulnerable to many adversarial attacks such as eavesdropping. Key establishment is one of the fundamental and widely studied countermeasures for securing the communications. In certain applications, the wireless devices may be energy-constrained, such as sensor nodes. Thus, energy intensive asymmetric key establishment protocols are infeasible. Additionally, in some scenarios, it is not practical to assume that all the devices pre-share certain secrets. Motivated by these observations, this paper presents an over-the-air key establishment protocol using keyless cryptography. Specifically, the proposed protocol is designed without using asymmetric key cryptography and pre-shared secrets. More specifically, our protocol provides a concrete construction to transform the wireless channel into an anonymous channel, and two wireless devices can establish a secret key by directly sending random signals to each other. The performance analysis shows that the energy consumption of our protocol is around 176 times cheaper than that of the Diffie–Hellman key exchange protocol. Additionally, it takes only 159.04 ms to establish a key with 112 secret bits.

Detecting Byzantine Attacks Without Clean Reference

We consider an amplify-and-forward relay network composed of a source, two relays, and a destination. In this network, the two relays are untrusted in the sense that they may perform Byzantine attacks by forwarding altered symbols to the destination. Note that every symbol received by the destination may be altered, and hence no clean reference observation is available to the destination. For this network, we identify a large family of Byzantine attacks that can be detected in the physical layer. We further investigate how the channel conditions impact the detection against this family of attacks. In particular, we prove that all Byzantine attacks in this family can be detected with asymptotically small miss detection and false alarm probabilities by using a sufficiently large number of channel observations \emph{if and only if} the network satisfies a non-manipulability condition. No pre-shared secret or secret transmission is needed for the detection of these attacks, demonstrating the value of this physical-layer security technique for counteracting Byzantine attacks.

HTTPAS: active authentication against HTTPS man‐in‐the‐middle attacks

Hypertext transfer protocol secure (HTTPS) relies on a group of pre-trusted certificate authorities (CAs) for authentication and hence can avoid man-in-the-middle attacks. However unfortunately, this authentication architecture can be completely subverted in case any one (usually the weakest one) of CAs has been compromised. To tackle this critical flaw, pioneer works such as notary-based systems and pre-shared secrets have been proposed. These state-of-the-art techniques can neither seek maximal protection from available CAs nor resist potential man-in-the-middle variants. In this study, the authors propose HTTPAS, a new HTTP Active Secure framework that can enhance the HTTPS authentication against man-in-the-middle attacks by actively utilising available CAs and exploiting Internet path diversity as much as possible. In particular, HTTPAS is designed with four practical solutions, each of which can make a unique trade-off among authentication capability, deployment difficulty and efficiency. They have implemented HTTPAS using the open secure sockets layer (SSL) suite, and also evaluated the implementation through experiments on several public certificate data sets and the Internet. Their results have successfully confirmed the authentication effectiveness of HTTPAS with only a few performance overheads and moderate deployment effort.

Authenticated quantum secret sharing with quantum dialogue based on Bell states

This work proposes a scheme that combines the advantages of a quantum secret sharing procedure and quantum dialogue. The proposed scheme enables the participants to simultaneously make mutual identity authentications, in a simulated scenario where the boss, Alice, shares a secret with her two agents Bob and Charlie. The secret is protected by checking photons to keep untrustworthy agents and outer attacks from getting useful information. Before the two agents cooperate to recover Alice’s secret, they must authenticate their identity using parts of a pre-shared key. In addition, the whole pre-shared key is reused as part of recovering the secret data to avoid any leaks of information. In comparison with previous schemes, the proposed method can efficiently detect eavesdropping and it is free from information leaks. Furthermore, the proposed scheme proved to be secure against man-in-the-middle attacks, impersonation attacks, entangled-and-measure attacks, participant attacks, modification attacks and Trojan-horse attacks.

Cumulated Checksum and Dynamic Addresses for Secure Wireless Sensor Networks

Due to the broadcast nature of wireless channel, attacks against wireless sensor networks are much easier to carry out as compared to wired networks. Passive attacks such as eavesdropping and traffic analysis cannot be eliminated even if cryptographic technologies are used. Conventional frames are usually designed to include checksum, which facilitates to adversaries capturing correct frames for further attacks. In most wireless sensor networks, source address and destination address at data link layer are unprotected, which makes traffic analysis quite easy. In this paper, we argue that the long-hold design principles of data link layer protocols are unreasonable from the perspective of wireless security. A secure ARQ scheme for wireless sensor networks named Sec-ARQ is proposed. Without the help of preshared keys or complex authentication infrastructure, Sec-ARQ protects frame checksum and addresses by cumulated checksum. Cumulated checksum is unknown to adversaries because of unavoidable wireless transmission errors. As frame checksum is unavailable to adversaries, error frames caused by collision cannot be detected, rendering eavesdropping useless. Addresses protection provided by cumulated checksum disables traffic analysis attacks. Sec-ARQ can defend against passive attacks effectively. Simulation results prove that Sec-ARQ can improve wireless security with little performance sacrifice, which is more suitable for resource-constrained wireless sensor networks.

NFC를 OOB 채널로 활용한 사물인터넷 보안 설정 기술

The PSK (Pre-shared Secret Key) based method is appropriate for the IoT environment consisting of lightweight devices since this method requires less computing time and energy than the method to configure the session key based on the public key algorithm. A fundamental prerequisite for the PSK based method is that PSK should have been configured between the communication entities safely in advance. However, in case of a small sensor or actuator, no input and output interface such as keyboard and monitor required for configuration exists, so it is more difficult to configure PSK for such lightweight devices safely in the IoT environment than the previous Internet devices. Especially, normal users lack expertise in security so they face difficulty in configuration. Therefore, the default value configured at the time of manufacturing at factories is used or the device installer configures PSK in most cases. In such case, it is a matter for consideration whether all installers and manufacturers can be trusted or not. In order to solve such problem, this paper proposes a secure bootstrapping scheme, which utilizes the NFC (Near Field Communication) as an OOB (Out-Of-Band) channel, for lightweight devices with limited resources.

MagPairing: Pairing Smartphones in Close Proximity Using Magnetometers

With the prevalence of mobile computing, lots of wireless devices need to establish secure communication on the fly without pre-shared secrets. Device pairing is critical for bootstrapping secure communication between two previously unassociated devices over the wireless channel. Using auxiliary out-of-band channels involving visual, acoustic, tactile, or vibrational sensors has been proposed as a feasible option to facilitate device pairing. However, these methods usually require users to perform additional tasks, such as copying, comparing, and shaking. It is preferable to have a natural and intuitive pairing method with minimal user tasks. In this paper, we introduce a new method, called MagPairing, for pairing smartphones in close proximity by exploiting correlated magnetometer readings. In MagPairing, users only need to naturally tap the smartphones together for a few seconds without performing any additional operations in authentication and key establishment. Our method exploits the fact that smartphones are equipped with tiny magnets. Highly correlated magnetic field patterns are produced when two smartphones are close to each other. We design MagPairing protocol and implement it on Android smartphones. We conduct extensive simulations and real-world experiments to evaluate MagPairing. Experiments verify that the captured sensor data on which MagPairing is based has high entropy and sufficient length, and is nondisclosure to attackers more than few centimeters away. Usability tests on various kinds of smartphones by totally untrained users show that the whole pairing process needs only 4.5 s on average with more than 90% success rate.

Authenticated B92 QKD protocol employing synchronized optical chaotic systems

Quantum key distribution (QKD) is not secure without an authentication protocol running together. The aim of the authentication protocol is to guarantees the identity of legitimate users, avoiding the man-in-the-middle attack. An authentication protocol requires an initially shared secret and it can be realized by software or by a physical system. In the first case a pseudo-random number generator (PRNG) is used while in the second case synchronized optical chaotic systems can be employed. In this direction, the present work considers both cases. Firstly, we show how to implement an authenticated polarization-based B92 QKD protocol using a PRNG. Its security is analyzed taking into account the number of bits of the pre-shared secret. Following, we describe a chaos-based authenticated B92 QKD protocol: We consider a chaotic system whose output is a light polarization state that changes chaotically and the synchronization of two of such systems. The Stokes’ parameter S1 of the output field is used to obtain a pseudo-random bit sequence that is used to implement the authentication. We emphasize functional limits for these two implementations.

Authenticated semi-quantum key distributions without classical channel

Yu et al. have proposed the first authenticated semi-quantum key distribution (ASQKD) without using an authenticated classical channel. This study further proposes two advanced ASQKD protocols. Compared to Yu et al.'s schemes, the proposed protocols ensure better qubit efficiency and require fewer pre-shared keys. Security analyses show that the proposed ASQKD protocols also can be secure against several well-known outside eavesdropper's attacks.

3AKEP: Triple-authenticated key exchange protocol for peer-to-peer VoIP applications

Peer-to-peer architectures have become very popular in the last years for a variety of services and applications they support, such as collaborative computing, streaming and VoIP applications. The security of the protocols involved in such operations is, however, a fundamental prerequisite for a widespread diffusion of such a technology. In this paper, we focus on the establishment of a security association in a distributed scenario and we propose a new key exchange protocol authenticated through three different methods: i) the verification of a signature, based on the identifier of the remote peer, ii) the use of retained secrets from previously established sessions with the same peer, iii) the exchange of a Short Authentication String through a proper “trusted means”. We also provide a possible implementation for peer-to-peer VoIP applications for setting up secure multimedia communications through the standard SIP protocol. Our proposal does not require pre-shared secrets, trusted third parties, nor a Public Key Infrastructure. In addition, we investigate different ways of distributing cryptographic peer identities in a sort of P2P web-of-trust. The proposed protocols have been also implemented and integrated into an open source SIP User Agent, for functional validation.

Random codekey selection using codebook without pre-shared keys for anti-jamming in WBAN

An implementation of Wireless Body Area Network (WBAN) plays an important role in the security of physiological data (e.g. ECG, EEG, etc.). On practical implementation, this WBAN faces physical layer attacks such as jamming and eavesdropping. These critical attacks cannot be defeated through conventional cryptographic methods. Thus, in order to counteract jamming and eavesdropping, spread spectrum techniques such as Direct Sequence Spread Spectrum (DSSS) and Frequency Hop Spread Spectrum (FHSS) have been adopted. The vulnerability in conventional spread spectrum is the requirement of pre-shared key between sender and receiver. But once the secret key is known to the jammer, then entire network is jammed. So to overcome the problem of pre-shared keys and to enhance the security of WBAN, the Random Codekey Selection using Codebook (RCSC) DSSS has been proposed in this work. The ratio of probability of breaking the code for 15 and 31 chip PN sequences of 100 trials is 56.86%. The RCSC DSSS can defeat the jamming attack with a high jamming probability of 0.18 for non-reactive jammers and 0.65 for reactive jammers with a codebook of size 500.

Investigating the Effectiveness and Performance of WPA_PSK (Pre-Shared Key) and WPA_RADIUS Server in Wireless Network Security

Investigating the Effectiveness and Performance of WPA_PSK (Pre-Shared Key) and WPA_RADIUS Server in Wireless Network Security

Detecting and Tracing i.i.d. Attacks in Networks With Any Number of Relays

This paper investigates the detection and tracing problems in a multi-relay network, where a source wants to exchange the information with a destination through multiple potential malicious relay nodes. We find that the destination could probabilistically detect the maliciousness in a multi-relay network if and only if the network satisfies a non-manipulable condition. Notice that the non-manipulable condition of the whole network is complicated to be checked. We divide the whole network into several sub-networks, and check the non-manipulability of the small-scale sub-networks in turn, which finally constitutes to a simplified checking method of the non-manipulable condition for the whole relay network. Furthermore, we propose a tracing algorithm to pinpoint the malicious relays individually in a multi-relay network if a tracing condition is satisfied. No pre-shared secret is needed in our proposed detecting and tracing schemes. Numerical examples are presented to validate the effectiveness of the proposed schemes.

S3K: Scalable Security With Symmetric Keys—DTLS Key Establishment for the Internet of Things

DTLS is becoming the de facto standard for communication security in the Internet of Things (IoT). In order to run the DTLS protocol, one needs to establish keys between the communicating devices. The default method of key establishment requires X.509 certificates and a Public Key Infrastructure, an approach which is often too resource consuming for small IoT devices. DTLS also supports the use of preshared keys and raw public keys. These modes are more lightweight, but they are not scalable to a large number of devices.

Polar Coding for Secret-Key Generation

Practical implementations of secret-key generation are often based on sequential strategies, which handle reliability and secrecy in two successive steps, called reconciliation and privacy amplification. In this paper, we propose an alternative approach based on polar codes that jointly deals with reliability and secrecy. Specifically, we propose secret-key capacity-achieving polar coding schemes for the following models: (i) the degraded binary memoryless source (DBMS) model with rate-unlimited public communication, (ii) the DBMS model with one-way rate-limited public communication, (iii) the 1-to-m broadcast model and (iv) the Markov tree model with uniform marginals. For models (i) and (ii) our coding schemes remain valid for non-degraded sources, although they may not achieve the secret-key capacity. For models (i), (ii) and (iii), our schemes rely on pre-shared secret seed of negligible rate; however, we provide special cases of these models for which no seed is required. Finally, we show an application of our results to secrecy and privacy for biometric systems. We thus provide the first examples of low-complexity secret-key capacity-achieving schemes that are able to handle vector quantization for model (ii), or multiterminal communication for models (iii) and (iv).

Probabilistic authenticated quantum dialogue

This work proposes a probabilistic authenticated quantum dialogue (PAQD) based on Bell states with the following notable features. (1) In our proposed scheme, the dialogue is encoded in a probabilistic way, i.e., the same messages can be encoded into different quantum states, whereas in the state-of-the-art authenticated quantum dialogue (AQD), the dialogue is encoded in a deterministic way; (2) the pre-shared secret key between two communicants can be reused without any security loophole; (3) each dialogue in the proposed PAQD can be exchanged within only one-step quantum communication and one-step classical communication. However, in the state-of-the-art AQD protocols, both communicants have to run a QKD protocol for each dialogue and each dialogue requires multiple quantum as well as classical communicational steps; (4) nevertheless, the proposed scheme can resist the man-in-the-middle attack, the modification attack, and even other well-known attacks.

Weak Locking Capacity of Quantum Channels Can be Much Larger Than Private Capacity

We show that it is possible for the so-called weak locking capacity of a quantum channel [Guha et al., PRX 4:011016, 2014] to be much larger than its private capacity. Both reflect different ways of capturing the notion of reliable communication via a quantum system while leaking almost no information to an eavesdropper; the difference is that the latter imposes an intrinsically quantum security criterion whereas the former requires only a weaker, classical condition. The channels for which this separation is most straightforward to establish are the complementary channels of classical-quantum (cq-)channels, and hence a subclass of Hadamard channels. We also prove that certain symmetric channels (related to photon number splitting) have positive weak locking capacity in the presence of a vanishingly small pre-shared secret, whereas their private capacity is zero. These findings are powerful illustrations of the difference between two apparently natural notions of privacy in quantum systems, relevant also to quantum key distribution (QKD): the older, naive one based on accessible information, contrasting with the new, composable one embracing the quantum nature of the eavesdropper's information. Assuming an additivity conjecture for constrained minimum output Renyi entropies, the techniques of the first part demonstrate a single-letter formula for the weak locking capacity of complements to cq-channels, coinciding with a general upper bound of Guha et al. for these channels. Furthermore, still assuming this additivity conjecture, this upper bound is given an operational interpretation for general channels as the maximum weak locking capacity of the channel activated by a suitable noiseless channel.

사물인터넷의 경량화 장치를 위한 안전한 Pre-shared Key 설정 기술

The IoT(Internet of things) technology enable objects around user to be connected with each other for sharing information. To support security is the mandatory requirement in IoT because it is related to the disclosure of private information but also directly related to the human safety. However, it is difficult to apply traditional security mechanism into lightweight devices. This is owing to the fact that many IoT devices are generally resource constrained and powered by battery. PSK(Pre-Shared Key) based approach, which share secret key in advance between communication entities thereafter operate security functions, is suitable for light-weight device. That is because PSK is costly efficient than a session key establishment approach based on public key algorithm. However, how to safely set a PSK of the lightweight device in advance is a difficult issue because input/output interfaces such as keyboard or display are constrained in general lightweight devices. To solve the problem, we propose and develop a secure PSK configuration scheme for resource constrained devices in IoT.

Formal modelling and analysis of DNP3 secure authentication

Supervisory Control and Data Acquisition (SCADA) systems are one of the key foundations of smart grids. The Distributed Network Protocol version 3 (DNP3) is a standard SCADA protocol designed to facilitate communications in substations and smart grid nodes. The protocol is embedded with a security mechanism called Secure Authentication (DNP3-SA). This mechanism ensures that end-to-end communication security is provided in substations. This paper presents a formal model for the behavioural analysis of DNP3-SA using Coloured Petri Nets (CPN). Our DNP3-SA CPN model is capable of testing and verifying various attack scenarios: modification, replay and spoofing, combined complex attack and mitigation strategies. Using the model has revealed a previously unidentified flaw in the DNP3-SA protocol that can be exploited by an attacker that has access to the network interconnecting DNP3 devices. An attacker can launch a successful attack on an outstation without possessing the pre-shared keys by replaying a previously authenticated command with arbitrary parameters. We propose an update to the DNP3-SA protocol that removes the flaw and prevents such attacks. The update is validated and verified using our CPN model proving the effectiveness of the model and importance of the formal protocol analysis.

ESC: An efficient, scalable, and crypto-less solution to secure wireless networks

In this paper we present ESC: an efficient, scalable, and crypto-less solution for the establishment of a secure wireless network (that is, a network where, for any pair of nodes, there exists a path composed of encrypted links).ESC guarantees the security of the 90% of the network scenario in the presence of 4 global eavesdropper adversaries with about 370 local peer-to-peer communications avoiding both pre-shared secrets and cryptographic functions.The founding block of our proposal is inspired by COKE [1], where the bits of the secret key associated to a link are generated via a multi-round protocol that, at each round, leverages just channel anonymity.Starting from this founding block, we further provide several relevant contributions: we devise a theoretical model and prove a lower bound for the probability to establish a safe-link in the presence of a global eavesdropper adversary. Further, we study the emergent property of network security achieved via the local property of safe-link establishment. To characterize this feature, we introduce two intuitive and useful metrics: network safety and largest safe component, both aimed at capturing the security features provided by ESC.The thorough theoretical analysis of our proposal, the security proof (under the Canetti–Krawczyk model) supporting our key establishment protocol, as well as our extensive simulations showing the effectiveness and efficiency of our protocol for a wide range of network configuration parameters, make our proposal a viable solution to enforce the security of real networks, other than paving the way for further research in this field.