Broadcast Authentication Research Articles

Securing Wireless Sensor Networks Against Broadcast Service Attacks

Attacks against broadcast services in wireless sensor networks will have the most catastrophic effects on power and other resource consumptions. As bogus broadcast packets are propagated through sensor nodes without being filtered out, sensor nodes will waste their resources such as power and memory on transmitting and buffering those false packets. In networks where complex Denial-of-Service (DoS) attacks may be launched, each node should be able to limit its effects on resource consumptions. In addition, it is strongly desired to identify compromised sensor node(s) which has injected invalid packets (intrusion detection) and to isolate the nodes (remediation) such that no more DoS attack is possible through the compromised sensor node(s) in the future. A new secure broadcast authentication scheme for sensor networks is proposed in this paper based upon predictive hashing and μTESLA techniques. This new scheme may be used to detect invalid packets as quickly as possible and to isolate links that are from the compromised nodes, which results in enhanced resistance to various security attacks including DoS attacks. We present the details of the scheme along with the simulation results.

Formal Reasoning about Physical Properties of Security Protocols

Traditional security protocols are mainly concerned with authentication and key establishment and rely on predistributed keys and properties of cryptographic operators. In contrast, new application areas are emerging that establish and rely on properties of the physical world. Examples include protocols for secure localization, distance bounding, and secure time synchronization. We present a formal model for modeling and reasoning about such physical security protocols. Our model extends standard, inductive, trace-based, symbolic approaches with a formalization of physical properties of the environment, namely communication, location, and time. In particular, communication is subject to physical constraints, for example, message transmission takes time determined by the communication medium used and the distance between nodes. All agents, including intruders, are subject to these constraints and this results in a distributed intruder with restricted, but more realistic, communication capabilities than those of the standard Dolev-Yao intruder. We have formalized our model in Isabelle/HOL and have used it to verify protocols for authenticated ranging, distance bounding, broadcast authentication based on delayed key disclosure, and time synchronization.

Accelerating signature-based broadcast authentication for wireless sensor networks

In wireless sensor networks (WSNs), broadcast authentication is a crucial security mechanism that allows a multitude of legitimate users to join in and disseminate messages into the networks in a dynamic and authenticated way. During the past few years, several public-key based multi-user broadcast authentication schemes have been proposed to achieve immediate authentication and to address the security vulnerability intrinsic to μTESLA-like schemes. Unfortunately, the relatively slow signature verification in signature-based broadcast authentication has also incurred a series of problems such as high energy consumption and long verification delay. In this contribution, we propose an efficient technique to accelerate the signature verification in WSNs through the cooperation among sensor nodes. By allowing some sensor nodes to release the intermediate computation results to their neighbors during the signature verification, a large number of sensor nodes can accelerate their signature verification process significantly. When applying our faster signature verification technique to the broadcast authentication in a 4×4 grid-based WSN, a quantitative performance analysis shows that our scheme needs 17.7–34.5% less energy and runs about 50% faster than the traditional signature verification method. The efficiency of the proposed technique has been tested through an experimental study on a network of MICAz motes.

“Verify-on-Demand” - A Practical and Scalable Approach for Broadcast Authentication in Vehicle-to-Vehicle Communication

In general for Vehicle-to-Vehicle (V2V) communication, message authentication is performed on every received wireless message by conducting verification for a valid signature, and only messages that have been successfully verified are processed further. In V2V safety communication, there are a large number of vehicles and each vehicle transmits safety messages frequently; therefore the number of received messages per second would be large. Thus authentication of each and every received message, for example based on the IEEE 1609.2 standard, is computationally very expensive and can only be carried out with expensive dedicated cryptographic hardware. An interesting observation is that most of these routine safety messages do not result in driver warnings or control actions since we expect that the safety system would be designed to provide warnings or control actions only when the threat of collision is high. If the V2V system is designed to provide too frequent warnings or control actions, then the system would be a nuisance to the driver. Therefore it is reasonable to define an approach where messages are first processed and then authenticated using verification on-demand. In this paper we describe such an approach and discuss its implementation for V2V safety system. It is shown that Verify-on-Demand (VoD) is a practical and scalable approach for broadcast authentication in V2V safety communication while conforming to the IEEE 1609.2 standard.

Improving Route Selection Mechanism using Trust Factor in AODV Routing Protocol for MaNeT

hoc network comprises of mobile nodes that cooperate with each other using wireless connections to route both data and control packets within the network. They are characterized by the use of wireless links, dynamically changing topology, multi-hop connectivity and decentralized routing mechanism and decision- making. The performance of Ad-hoc On Demand Vector (AODV) protocols has been modified by including the source route accumulation feature. As low transmission power of each ad-hoc node limits its communication range, the nodes must assist and trust each other in forwarding packets from one node to another. However, this implied trust relationship can be threatened by malicious nodes that may fabricate, modify or disrupt the orderly exchange of packets. Security demands that all packets be authenticated before being used. A particularly hard problem is to provide efficient broadcast authentication, which is important mechanism for MaNet. In this paper, we propose a routing algorithm which adds a field in request packet which stores trust value indicating node trust on neighbour. Based on level of trust factor, the routing information will be transmitted depending upon highest trust value among all. This not only saves the node's power by avoiding unnecessary transmitting control information but also in terms of bandwidth (channel utilization), which is very important in case of MaNet. The malicious node can attack on the control packet and misbehave in the network .The malicious node, which may or may not be trusted node. In this paper, we use trusted path irrespective of shortest or longest path which can be used for communication in the network. We are able to calculate route trust value on the complete reply path which can be utilized by source node for next forthcoming communication in the network.

Broadcast Authentication for Wireless Sensor Networks Using Nested Hashing and the Chinese Remainder Theorem

Secure broadcasting is an essential feature for critical operations in wireless sensor network (WSNs). However, due to the limited resources of sensor networks, verifying the authenticity for broadcasted messages is a very difficult issue. μTESLA is a broadcast authentication protocol, which uses network-wide loose time synchronization with one-way hashed keys to provide the authenticity verification. However, it suffers from several flaws considering the delay tolerance, and the chain length restriction. In this paper, we propose a protocol which provides broadcast authentication for wireless sensor networks. This protocol uses a nested hash chain of two different hash functions and the Chinese Remainder Theorem (CRT). The two different nested hash functions are employed for the seed updating and the key generation. Each sensor node is challenged independently with a common broadcasting message using the CRT. Our algorithm provides forward and non-restricted key generation, and in addition, no time synchronization is required. Furthermore, receivers can instantly authenticate packets in real time. Moreover, the comprehensive analysis shows that this scheme is efficient and practical, and can achieve better performance than the μTESLA system.

Secure and Efficient Broadcast Authentication in Wireless Sensor Networks

Authenticated broadcast, enabling a base station to send commands and requests to low-powered sensor nodes in an authentic manner, is one of the core challenges for securing wireless sensor networks. μTESLA and its multilevel variants based on delayed exposure of one-way chains are well known valuable broadcast authentication schemes, but concerns still remain for their practical application. To use these schemes on resource-limited sensor nodes, a 64-bit key chain is desirable for efficiency, but care must be taken. We will first show, by both theoretical analysis and rigorous experiments on real sensor nodes, that if μTESLA is implemented in a raw form with 64-bit key chains, some of the future keys can be discovered through time-memory-data-tradeoff techniques. We will then present an extendable broadcast authentication scheme called X-TESLA, as a new member of the TESLA family, to remedy the fact that previous schemes do not consider problems arising from sleep modes, network failures, idle sessions, as well as the time-memory-data tradeoff risk, and to reduce their high cost of countering DoS attacks. In X-TESLA, two levels of chains that have distinct intervals and cross-authenticate each other are used. This allows the short key chains to continue indefinitely and makes new interesting strategies and management methods possible, significantly reducing unnecessary computation and buffer occupation, and leads to efficient solutions to the raised problems.

Denial of service attack-resistant flooding authentication in wireless sensor networks

To achieve scalable and efficient broadcast authentication in large-scale networks, two asymmetry mechanisms have often been employed: the cryptographic asymmetry and the time asymmetry. Authentication schemes using digital signatures are based on the cryptographic asymmetry, while TESLA and related protocols using hash chains and delayed-key release methods are based on the time asymmetry. However, the former is computationally expensive while the latter provides delayed authentication only. Therefore, they are vulnerable to denial of service attacks that repeatedly request signature verifications with false messages. In this paper, we propose a novel broadcast authentication mechanism based on our “Information Asymmetry” model. It leverages an asymmetric distribution of keys between a sink and sensor nodes and uses the Bloom filter as an authenticator, which efficiently compresses multiple authentication information. In addition, with a novel “false negative” tuning knob introduced in construction of the Bloom filter, we show that scalability of our authentication method can greatly be improved. Through an intensive analysis, we demonstrate optimized trade-off relationships between resiliency against compromised nodes and scalability of system size. Optimization results indicate that the proposed authentication scheme achieves low false positive rates with small signature verification costs.

Universally composable one-time signature and broadcast authentication

Broadcast authentication is a vital security primitive for the management of a copious number of parties. In the universally composable framework, this paper investigates broadcast authentication using one-time signature based on the fact that one-time signature has efficient signature generation and verification suitable for low-power devices, and gives immediate authentication, which is a favorable property for time-critical messages. This paper first formulates a broadcast authentication model with the ideal functionalities such as one-time signature and broadcast authentication, and proposes a broadcast authentication scheme in the hybrid model. This paper then improves HORS, which is secure based on a strong assumption (i.e., a subset-resilient hash function) and presents the improved version as HORS+, which differs from HORS such that it is a secure one-time signature based on weaker assumptions, i.e. one-way functions, one-way hash functions and collision-resistant hash functions. At the same time, a protocol OWC using one-way chains is proposed to provide more registered keys for multi-message broadcast authentication. Our broadcast authentication scheme constructed by the combined use of HORS+ and OWC is universally composable secure and suitable for low-power devices.

ShortPK

Broadcast authentication is an important functionality in sensor networks. Energy constraints on sensor nodes and the real-time nature of the broadcasts render many of the existing solutions impractical: previous works focusing primarily on symmetric key schemes have difficulties in achieving real-time authentication. Public Key Cryptography (PKC), however, can satisfy the real-time requirements, and recent trends indicate that public key is becoming feasible for sensor networks. However, PKC operations are still expensive computations. It is impractical to use PKC in the conventional ways for broadcast authentication in sensor networks. To reduce costs, we propose ShortPK , an efficient Short-term Public Key broadcast authentication scheme. The basic idea is to use short-length public/private keys, but limit their lifetime to only a short period of time. To cover a long period of time, we need to use many public/private key pairs; distributing these public keys to sensors is a challenging problem. We describe a progressive key distribution scheme that is secure, efficient, and packet-loss resilient. We compare our scheme with the traditional 160-bit ECC public key schemes, and show that our scheme can achieve a significant improvement on energy consumption.

Flexible, extensible, and efficient VANET authentication

Although much research has been conducted in the area of authentication in wireless networks, vehicular ad-hoc networks (VANETs) pose unique challenges, such as real-time constraints, processing limitations, memory constraints, frequently changing senders, requirements for interoperability with existing standards, extensibility and flexibility for future requirements, etc. No currently proposed technique addresses all of the requirements for message and entity authentication in VANETs. After analyzing the requirements for viable VANET message authentication, we propose a modified version of TESLA, TESLA++, which provides the same computationally efficient broadcast authentication as TESLA with reduced memory requirements. To address the range of needs within VANETs we propose a new hybrid authentication mechanism, VANET authentication using signatures and TESLA++ (VAST), that combines the advantages of ECDSA signatures and TESLA++. Elliptic curve digital signature algorithm (ECDSA) signatures provide fast authentication and non-repudiation, but are computationally expensive. TESLA++ prevents memory and computation-based denial of service attacks. We analyze the security of our mechanism and simulate VAST in realistic highway conditions under varying network and vehicular traffic scenarios. Simulation results show that VAST outperforms either signatures or TESLA on its own. Even under heavy loads VAST is able to authenticate 100% of the received messages within 107ms. VANETs use certificates to achieve entity authentication (i.e., validate senders). To reduce certificate bandwidth usage, we use Hu et al.'s strategy of broadcasting certificates at fixed intervals, independent of the arrival of new entities. We propose a new certificate verification strategy that prevents denial of service attacks while requiring zero additional sender overhead. Our analysis shows that these solutions introduce a small delay, but still allow drivers in a worst case scenario over 3 seconds to respond to a dangerous situation.

Multi-User Broadcast Authentication in Wireless Sensor Networks

Broadcast authentication is a critical security service in wireless sensor networks (WSNs), as it allows mobile users of WSNs to broadcast messages to multiple sensor nodes in a secure way. Although symmetric-key-based solutions such as muTESLA and multilevel muTESLA have been proposed, they all suffer from severe energy-depletion attacks resulting from the nature of delayed message authentication. This paper presents several efficient public-key-based schemes to achieve immediate broadcast authentication and thus avoid the security vulnerability that is intrinsic to muTESLA-like schemes. Our schemes are built upon the unique integration of several cryptographic techniques, including the Bloom filter, the partial message-recovery signature scheme, and the Merkle hash tree. We prove the effectiveness and efficiency of the proposed schemes by a comprehensive quantitative analysis of their energy consumption in both computation and communication.

Applied Cryptography for Security and Privacy in Wireless Sensor Networks

It is challenging to secure a wireless sensor network (WSN) because its inexpensive, tiny sensor nodes do not have the necessary processing capability, memory capacity, and battery life to take advantage of the existing security solutions for traditional networks. Existing security solutions for wireless sensor networks are mostly based on symmetric key cryptography with the assumption that sensor nodes are embedded with secret, temporary startup keys before deployment thus avoiding any use of computationally demanding public key algorithms altogether. However, symmetric key cryptography alone cannot satisfactorily provide all security needs for wireless sensor networks. It is still problematic to replenish an operational wireless sensor network with new sensor nodes securely. Current research on public key cryptography for WSNs shows some promising results, particularly in the use of elliptic curve cryptography and identity based encryption for WSNs. Although security is essential for WSNs, it can complicate some crucial operations of a WSN like data aggregation or in-network data processing that can be affected by a particular security protocol. Accordingly, in this paper, we summarize, discuss, and evaluate recent symmetric key based results reported in literature on sensor network security protocols such as for key establishment, random key pre-distribution, data confidentiality, data integrity, and broadcast authentication as well as expose limitations and issues related to those solutions for WSNs. We also present significant advancement in public key cryptography for WSNs with promising results from elliptic curve cryptography and identity based encryption as well as their limitations for WSNs.

A Novel Re-keying Function Protocol (NRFP) For Wireless Sensor Network Security.

This paper describes a novel re-keying function protocol (NRFP) for wireless sensor network security. A re-keying process management system for sensor networks is designed to support in-network processing. The design of the protocol is motivated by decentralization key management for wireless sensor networks (WSNs), covering key deployment, key refreshment, and key establishment. NRFP supports the establishment of novel administrative functions for sensor nodes that derive/re-derive a session key for each communication session. The protocol proposes direct connection, in-direct connection and hybrid connection. NRFP also includes an efficient protocol for local broadcast authentication based on the use of one-way key chains. A salient feature of the authentication protocol is that it supports source authentication without precluding innetwork processing. Security and performance analysis shows that it is very efficient in computation, communication and storage and, that NRFP is also effective in defending against many sophisticated attacks.

Integrity Codes: Message Integrity Protection and Authentication over Insecure Channels

Inspired by unidirectional error detecting codes that are used in situations where only one kind of bit errors are possible (e.g., it is possible to change a bit "0" into a bit "1", but not the contrary), we propose integrity codes (I-codes) for a radio communication channel, which enable integrity protection of messages exchanged between entities that do not hold any mutual authentication material (i.e. public keys or shared secret keys). The construction of I-codes enables a sender to encode any message such that if its integrity is violated in transmission over a radio channel, the receiver is able to detect it. In order to achieve this, we rely on the physical properties of the radio channel and on unidirectional error detecting codes. We analyze in detail the use of I-codes on a radio communication channel and we present their implementation on a wireless platform as a "proof of concept". We further introduce a novel concept called "authentication through presence", whose broad applications include broadcast authentication, key establishment and navigation signal protection. We perform a detailed analysis of the security of our coding scheme and we show that it is secure within a realistic attacker model.

Secure and Reliable Broadcasting Based on Cooperative Diversity in Wireless Ad Hoc Networks

In wireless ad hoc networks, providing an authentication service to verify that the broadcast packet is from the claimed sender without modification, is challenging due mainly to the inherently lossy wireless links. This paper presents a novel Secure and Reliable Broadcasting that reinforces the broadcast authentication with reliability and energy-efficiency capabilities by using the cooperative diversity to superimpose two distinct signals. The proposed protocol achieves significant savings of transmission power and fair assurance of reliability among receivers.

SEAR: a secure efficientad hocon demand routing protocol for wireless networks

AbstractMulti‐hop routing is essential to the operation of wirelessad hocnetworks. Unfortunately, it is very easy for an adversary to forge or modify routing messages to inflict severe damage on the underlying routing protocol. In this paper, we present SEAR, a secure efficientad hocrouting (SEAR) protocol forad hocnetworks that is mainly based on efficient symmetric cryptography, with asymmetric cryptography used only for the distribution of initial key commitments. SEAR uses one‐way hash functions to protect the propagation of the routing messages. Intermediate nodes verify the routing messages by applying one‐way functions, while malicious nodes cannot construct beneficial false routing messages when forwarding them. Route error (RERR) messages are protected through a variation of the TESLA broadcast authentication scheme. The SEAR protocol does not require any additional routing packet formats, and thus follows the same basic design asad hocon‐demand distance vector (AODV). We show, through both theoretical examination and simulations, that SEAR provides better security with significantly less overhead than other existing secure AODV (SAODV) protocols. Copyright © 2008 John Wiley & Sons, Ltd.

Broadcast Authentication with Practically Unbounded One-way Chains

A protocol for assuring the authenticity of information broadcasted over long periods of time is proposed. The protocol is based on time synchronization and uses one-way chains constructed with the squaring function which gives the possibility to construct a one-way chain of whose length is unbounded in practice. Although the computational cost is somewhat increased, compared to the use of hash chains, these computational requirements are affordable for the addressed scenario. In brief, the protocol assures information authenticity at the reduced cost of almost one modular multiplication for each broadcasted packet. Time synchronization issues are discussed and the security of the protocol is equivalent to the integer factorization problem since the squaring function is used in the construction of the one-way chain. A failure mode analysis of the protocol is done; this is an aspect of novelty and applies to other protocols based on time synchronization as well. Also, a formal proof on the security of the protocol is sketched.

Mitigating DoS attacks against broadcast authentication in wireless sensor networks

Broadcast authentication is a critical security service in wireless sensor networks. There are two general approaches for broadcast authentication in wireless sensor networks: digital signatures and μTESLA-based techniques. However, both signature-based and μTESLA-based broadcast authentication are vulnerable to Denial of Services (DoS) attacks: An attacker can inject bogus broadcast packets to force sensor nodes to perform expensive signature verifications (in case of signature-based broadcast authentication) or packet forwarding (in case of μTESLA-based broadcast authentication), thus exhausting their limited battery power. This paper presents an efficient mechanism called message-specific puzzle to mitigate such DoS attacks. In addition to signature-based or μTESLA-based broadcast authentication, this approach adds a weak authenticator in each broadcast packet, which can be efficiently verified by a regular sensor node, but takes a computationally powerful attacker a substantial amount of time to forge. Upon receiving a broadcast packet, each sensor node first verifies the weak authenticator, and performs the expensive signature verification (in signature-based broadcast authentication) or packet forwarding (in μTESLA-based broadcast authentication) only when the weak authenticator is valid. A weak authenticator cannot be precomputed without a non-reusable (or short-lived) key disclosed only in a valid packet. Even if an attacker has intensive computational resources to forge one or more weak authenticators, it is difficult to reuse these forged weak authenticators. Thus, this weak authentication mechanism substantially increases the difficulty of launching successful DoS attacks against signature-based or μTESLA-based broadcast authentication. A limitation of this approach is that it requires a powerful sender and introduces sender-side delay. This article also reports an implementation of the proposed techniques on TinyOS, as well as initial experimental evaluation in a network of MICAz motes.

On Broadcast Authentication in Wireless Sensor Networks

Broadcast authentication is a critical security service in wireless sensor networks (WSNs), since it enables users to broadcast the WSN in an authenticated way. Symmetric key based schemes such as muTESLA and multilevel muTESLA have been proposed to provide such services for WSNs; however, these schemes all suffer from serious DoS attacks due to the delay in message authentication. This paper presents several effective public key based schemes to achieve immediate broadcast authentication and thus overcome the vulnerability presented in the muTESLA-like schemes. Several cryptographic techniques, including Merkle hash tree and identity-based signature scheme, are adopted to minimize the scheme overhead regarding the costs on both computation and communication. A quantitative energy consumption analysis of the proposed schemes is given in detail. We believe that this paper can serve as the start point towards fully solving the important multisender broadcast authentication problem in WSNs.