Pre-shared Secret Keys Research Articles

Quantum Key Distribution with Post-Processing Driven by Physical Unclonable Functions

Quantum key distribution protocols allow two honest distant parties to establish a common truly random secret key in the presence of powerful adversaries, provided that the two users share a short secret key beforehand. This pre-shared secret key is used mainly for authentication purposes in the post-processing of classical data that have been obtained during the quantum communication stage, and it prevents a man-in-the-middle attack. The necessity of a pre-shared key is usually considered to be the main drawback of quantum key distribution protocols, and it becomes even stronger for large networks involving more than two users. Here, we discuss the conditions under which physical unclonable functions can be integrated in currently available quantum key distribution systems in order to facilitate the generation and the distribution of the necessary pre-shared key with the smallest possible cost in the security of the systems. Moreover, the integration of physical unclonable functions in quantum key distribution networks allows for real-time authentication of the devices that are connected to the network.

An Observer-Based Key Agreement Scheme for Remotely Controlled Mobile Robots

Remotely controlled mobile robots are important examples of Cyber–Physical Systems (CPSs) that are being deployed in many safety critical applications. Different control schemes that have been proposed to secure such systems against sophisticated cyber-attacks require the exchange of secret messages between their smart actuators and the remote controller. Thus, these schemes require pre-shared secret keys, or an established Public Key Infrastructure that allows for key agreement. Such cryptographic approaches might not always be suitable for the deployment environments of such remotely mobile robots. To address this problem, in this paper, we consider a control theoretic approach for establishing a secret key between the remotely controlled robot and the networked controller without resorting to traditional cryptographic techniques. Our key agreement scheme leverages a nonlinear unknown input observer and an error correction code mechanism to allow the robot to securely agree on a secret key with its remote controller. The effectiveness of the proposed solution is shown by mean of experimental results obtained using a Khepera-IV robot.

A Key Management Protocol Based on the Hash Chain Key Generation for Securing LoRaWAN Networks.

Recently, many Low Power Wide Area Network (LPWAN) protocols have been proposed for securing resource-constrained Internet of Things (IoT) devices with negligible power consumption. The Long Range Wide Area Network (LoRaWAN) is a low power communication protocol that supports message authentication, integrity, and encryption using two-session preshared secret keys. However, although the LoRaWAN supports some security functions, it suffers from session key generation and key update problems. This motivates us to introduce a new key management protocol that resolves the LoRaWAN problems and supports key updates. The proposed protocol is based on hash chain generation using a one-way hash function. Network entities share a common hash chain of n key elements to allow using a unique signing key per message. We also propose a salt hashing algorithm that encrypts the original keys into a different form to avoid the physical attacks at the end device side. We analyzed the proposed key generation performance in terms of the computation time, the required storage, and the communication overhead. We implemented and tested the proposed key generation protocol using the NS-3 network simulator. The proposed lightweight key generation protocol significantly enhances the security of the original LoRaWAN at a negligible overhead. The proposed protocol reduces the power consumption and transmission time by two times compared with some previous protocols. In addition, the proposed key generation protocol can resist attacks, such as key compromising attacks and replay attacks, and it supports the Perfect Forward Secrecy, which was not supported by LoRaWAN.

Prudently Secure Information Theoretic LSB Steganography for Digital Grayscale Images

The endangerment of online data breaches calls for exploring new and enhancing existing sneaky ways of clandestine communication to tailor those to match the present and futuristic technological and environmental needs, to which malicious intruders wouldn't have an answer. Cryptography and Steganography are the two distinct techniques that, for long, have remained priority choices for hiding vital information from the unauthorized. But the visibility of the encrypted contents makes these vulnerable to attack. Also, the recent legislative protection agreed to law enforcement authorities in Australia to sneak into pre-shared cryptographic secret keys (PSKs) shall have a devastating impact on the privacy of the people. Hence, the need of the hour is to veil in the encrypted data underneath the cover of Steganography, whose sole intent is to hide the very existence of information. This research endeavor enhances one of the most famous images Steganography technique called the Least Significant Bit (LSB) Steganography, from the security and information-theoretic standpoint by taking a known-cover and known-message attack scenario. The explicit proclamation of this research endeavor is that the security of LSB Steganography lies in inducing uncertainty at the time of bit embedding process. The test results rendered by the proposed methodology confers on the non-detectability and imperceptibility of the confidential information along with its strong resistance against LSB Steganalysis techniques.

Design and realization of efficient & secure multi-homed systems based on random linear network coding

Multi-homing is a new mechanism that enables hosts with multiple network interfaces (IP addresses), to connect to more than one data link. This technology enhances Internet connectivity and reliability without compromising efficient performance. Like any communication system, the security of multi-homed systems is of great importance. However, this issue remains largely un-attempted, where only few papers in the literature discuss, address and present security solutions for multi-homed systems. On the other hand, Random Linear Network Coding (RLNC) has recently emerged as a new coding technique that aims at improving system performance by efficiently transmitting and compressing data in general multi-source multicast networks. In this paper, a data confidentiality and availability scheme based on RNLC, is proposed for multi-homed systems. The proposed solution exploits the random physical characteristics of wireless channels, along with a pre-shared secret key, to derive dynamic keys which are used to generate random and dynamic cryptographic primitives. These primitives mainly include two permutation tables and a set of secret invertible RLNC matrices, all of which change for every input message. It has been shown that by securing the cryptographic primitives needed in the ciphering/deciphering process, one can jointly enhance the security and performance of transmitted data in multi-homed systems. Finally, security and performance analysis are presented to validate the efficiency and security of the proposed encryption/encoding scheme.

Semantic Security with Practical Transmission Schemes over Fading Wiretap Channels

We propose and assess an on–off protocol for communication over wireless wiretap channels with security at the physical layer. By taking advantage of suitable cryptographic primitives, the protocol we propose allows two legitimate parties to exchange confidential messages with some chosen level of semantic security against passive eavesdroppers, and without needing either pre-shared secret keys or public keys. The proposed method leverages the noisy and fading nature of the channel and exploits coding and all-or-nothing transforms to achieve the desired level of semantic security. We show that the use of fake packets in place of skipped transmissions during low channel quality periods yields significant advantages in terms of time needed to complete transmission of a secret message. Numerical examples are provided considering coding and modulation schemes included in the WiMax standard, thus showing that the proposed approach is feasible even with existing practical devices.

ISAP – Towards Side-Channel Secure Authenticated Encryption

Side-channel attacks and in particular differential power analysis (DPA) attacks pose a serious threat to cryptographic implementations. One approach to counteract such attacks are cryptographic schemes based on fresh re-keying. In settings of pre-shared secret keys, such schemes render DPA attacks infeasible by deriving session keys and by ensuring that the attacker cannot collect side-channel leakage on the session key during cryptographic operations with different inputs. While these schemes can be applied to secure standard communication settings, current re-keying approaches are unable to provide protection in settings where the same input needs to be processed multiple times. In this work, we therefore adapt the re-keying approach and present a symmetric authenticated encryption scheme that is secure against DPA attacks and that does not have such a usage restriction. This means that our scheme fully complies with the requirements given in the CAESAR call and hence, can be used like other noncebased authenticated encryption schemes without loss of side-channel protection. Its resistance against side-channel analysis is highly relevant for several applications in practice, like bulk storage settings in general and the protection of FPGA bitfiles and firmware images in particular.

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.

A Secure Information Transmission Scheme With a Secret Key Based on Polar Coding

In this letter, a new secure information transmission scheme based on polar codes with a pre-shared secret key is proposed. In polar codes, after the channel polarization is induced, good split channels are used to transmit the user message and bad channels are utilized to support the reconstruction of the message by sharing fixed information. If the fixed information in bad channels is secret, an adversary gets difficulty in reconstructing the user message in good channels without knowledge of the fixed information. From this observation, we construct a secure information transmission scheme. By appending pre-/post-processing that imposes a dependency between the transmitted message sub-blocks, the adversary's difficulty can be changed to an intractability, since only partial information can be decodable by attackers. A new class of secret key scheme is developed in such a way.

Communication Efficiency of Anti-Jamming Broadcast in Large-Scale Multi-Channel Wireless Networks

Uncoordinated Frequency Hopping (UFH) and Collaborative UFH (CUFH) are viable countermeasures for jamming attacks without dependency on pre-shared secret keys. In this work we analytically evaluate their communication efficiency in large-scale networks, where the number of nodes n is large and may even exceed the number of channels C. Such a large-system analysis is pertinent to emerging complex networks and systems, and helps us reveal the scaling behavior of the system performance with respect to the network size and other important system parameters. In particular, we show that the average network broadcast delay incurred by UFH scales as O(Clnn) , while that incurred by CUFH scales as O(lnn) when C=o(lnn). This demonstrates a significant improvement achieved by cooperative relays and the feasibility of UFH-based schemes in large-scale networks. In large-scale networks, the number of relays in CUFH needs to be carefully controlled for best performance. In this study the optimal number of relays in CUFH is derived such that the packet reception rate is maximized, and the optimal cooperation gain achieved by CUFH over UFH is quantified. To facilitate the implementation of CUFH, a suboptimal protocol, CUFH-p, is proposed, which achieves the optimal cooperation gain asymptotically. As an intermediate step, we also study an ideal cooperative network, whose results may be of independent interest. Our analytical results are well substantiated by simulations, and our analytical methodology applies largely to general anti-jamming broadcast in multi-channel networks.

Simple Post Quantum Scheme for Higher Key Rate Multiparty Quantum Key Distribution

We propose a multi-party quantum key distribution protocol which enables all the receivers can convert their respective private shared key into common secret key without use of entanglement. The main component of our protocol is a simple post quantum scheme for achieving the higher secret key rate. Efficiency of the extracted key rate is almost 100%. We assume that sender established the pre-shared private secret keys and a common secret number with the receivers. Our proposed scheme sends n strings of number to n receivers in the public channel to convert their respective shared secret key into common secret key in the presence of Eve. We also analyze the complexity of attack by the adversary to guess the secret key.

Physical Layer Authentication over MIMO Fading Wiretap Channels

In a wide band and multipath rich environment, precise channel estimation allows authenticating the source and protecting the integrity of a message at the physical layer without the need of a pre-shared secret key. This allows also a reduction of the burden on the authentication protocols at higher layers. In this paper we develop an authentication scheme in the framework of hypothesis testing that suits a multiple wiretap channels environment with correlated fading, as is the case of multiple input multiple output (MIMO) systems and/or orthogonal frequency division multiplexing (OFDM) modulation. By allowing some degree of correlation among the channels, we formulate the optimal attack strategy for the cases of both single attempt and multiple repeated trials. For the latter scenario, due to the complexity of the optimal solution, we also develop a simpler suboptimal attack strategy. The performance of the proposed methods is evaluated in a MIMO/OFDM scenario and numerical results show the merits of the proposed approaches that can be adopted as a layer one authentication mechanism.

MAC Design of Uncoordinated FH-Based Collaborative Broadcast

Uncoordinated Frequency Hopping (UFH) techniques are promising to address jamming attacks in wireless networks without requiring pre-shared secret keys, and its communication efficiency in the broadcast scenario can be significantly improved through node cooperation. In this letter, we take a first step to investigate efficient Media Access Control (MAC) strategies for the UFH-based collaborative broadcast, and derive closed-form expressions of the channel access probabilities for time-slotted systems to minimize the broadcast delay and to significantly reduce the energy cost. Numerical and simulation results are provided to verify our analysis and reveal some insights.

A scheme for authentication and dynamic key exchange in wireless networks

Despite significant shortcomings in the initial security architecture, 802.11 wireless LANs have experienced explosive growth in recent years. Ongoing work in IEEE standards bodies is currently attempting to fix these shortcomings. One specific topic that has received extensive attention is how to enable these networks to authenticate users and to dynamically establish per-user per-session cryptographic keys. The IEEE 802.1x Port-Based Access Control standard, which formalizes a new EAP-over-LAN (EAPOL) protocol, has emerged as the preferred way to achieve this. The EAPOL protocol employs the extensible authentication protocol (EAP), standardized by the Internet Engineering Task Force, to allow the use of existing and new authentication methods and authentication, authorization, and accounting (AAA) infrastructure. In this paper we present a new EAP scheme — called shared key exchange (SKE) — suitable for use in 802.11 private or public access wireless LANs. The scheme relies on secure pre-shared secret keys in wireless LAN mobile nodes devices and AAA servers. When instantiated with relatively minor changes to RADIUS and EAP, the resulting protocol is provably secure and offers a full set of security features. A second, simplified protocol results from minimal modifications to existing RADIUS and EAP standards, but it provides a lower level of security. Both protocols efficiently support roaming scenarios wherein an end user roams across different networks and requires frequent re-authentication with low latency. The protocols can easily be extended to support migration to new AAA protocols such as DIAMETER.