Efficient signature verification and key revocation using identity based cryptography

Cryptography deals with the development and evaluation of procedures for securing digital information. It is essential whenever multiple entities want to communicate safely. One task of cryptography concerns digital signatures and the verification of a signer’s legitimacy requires trustworthy authentication and authorization. This is achieved by deploying cryptographic keys. When dynamic membership behavior and identity theft come into play, revocation of keys has to be addressed. Additionally, in use cases with limited networking, computational, or storage resources, efficiency is a key requirement for any solution. In this work we present a solution for signature verification and key revocation in constraned environments, e.g., in the Internet of Things (IoT). Where other mechanisms generate expensive overheads, we achieve revocation through a single multicast message without significant computational or storage overhead. Exploiting Identity Based Cryptography (IBC) complements the approach with efficient creation and verification of signatures. Our solution offers a framework for transforming a suitable signature scheme to a so-called Key Updatable Signature Scheme (KUSS) in three steps. Each step defines mathematical conditions for transformation and precise security notions. Thereby, the framework allows a novel combination of efficient Identity Based Signature (IBS) schemes with revocation mechanisms originally designed for confidentiality in group communications. Practical applicability of our framework is demonstrated by transforming four well-established IBS schemes based on Elliptic Curve Cryptography (ECC). The security of the resulting group Identity Based Signature (gIBS) schemes is carefully analyzed with techniques of Provable Security. We design and implement a testbed for evaluating these kind of cryptographic schemes on different computing- and networking hardware, typical for constrained environments. Measurements on this testbed provide evidence that the transformations are practicable and efficient. The revocation complexity in turn is significantly reduced compared to existing solutions. Some of our new schemes even outperform the signing process of the widely used Elliptic Curve Digital Signature Algorithm (ECDSA). The presented transformations allow future application on schemes beyond IBS or ECC. This includes use cases dealing with Post-Quantum Cryptography, where the revocation efficiency is similarly relevant. Our work provides the basis for such solutions currently under investigation.Die Kryptographie ist ein Instrument der Informationssicherheit und beschäftigt sich mit der Entwicklung und Evaluierung von Algorithmen zur Sicherung digitaler Werte. Sie ist für die sichere Kommunikation zwischen mehreren Entitäten unerlässlich. Ein Bestandteil sind digitale Signaturen, für deren Erstellung man kryptographische Schlüssel benötigt. Bei der Verifikation muss zusätzlich die Authentizität und die Autorisierung des Unterzeichners gewährleistet werden. Dafür müssen Schlüssel vertrauensvoll verteilt und verwaltet werden. Wenn sie in Kommunikationssystemen mit häufig wechselnden Teilnehmern zum Einsatz kommen, müssen die Schlüssel auch widerruflich sein. In Anwendungsfällen mit eingeschränkter Netz-, Rechen- und Speicherkapazität ist die Effizienz ein wichtiges Kriterium. Diese Arbeit liefert ein Rahmenwerk, mit dem Schlüssel effizient widerrufen und Signaturen effizient verifiziert werden können. Dabei fokussieren wir uns auf Szenarien aus dem Bereich des Internets der Dinge (IoT, Internet of Things). Im Gegensatz zu anderen Lösungen ermöglicht unser Ansatz den Widerruf von Schlüsseln mit einer einzelnen Nachricht innerhalb einer Kommunikationsgruppe. Dabei fällt nur geringer zusätzlicher Rechen- oder Speicheraufwand an. Ferner vervollständigt die Verwendung von Identitätsbasierter Kryptographie (IBC, Identity Based Cryptography) unsere Lösung mit effizienter Erstellung und Verifikation der Signaturen. Hierfür liefert die Arbeit eine dreistufige mathematische Transformation von geeigneten Signaturverfahren zu sogenannten Key Updatable Signature Schemes (KUSS). Neben einer präzisen Definition der Sicherheitsziele werden für jeden Schritt mathematische Vorbedingungen zur Transformation festgelegt. Dies ermöglicht die innovative Kombination von Identitätsbasierten Signaturen (IBS, Identity Based Signature) mit effizienten und sicheren Mechanismen zum Schlüsselaustausch, die ursprünglich für vertrauliche Gruppenkommunikation entwickelt wurden. Wir zeigen die erfolgreiche Anwendung der Transformationen auf vier etablierten IBSVerfahren. Die ausschließliche Verwendung von Verfahren auf Basis der Elliptic Curve Cryptography (ECC) erlaubt es, den geringen Kapazitäten der Zielgeräte gerecht zu werden. Eine Analyse aller vier sogenannten group Identity Based Signature (gIBS) Verfahren mit Techniken aus dem Forschungsgebiet der Beweisbaren Sicherheit zeigt, dass die zuvor definierten Sicherheitsziele erreicht werden. Zur praktischen Evaluierung unserer und ähnlicher kryptographischer Verfahren wird in dieser Arbeit eine Testumgebung entwickelt und mit IoT-typischen Rechen- und Netzmodulen bestückt. Hierdurch zeigt sich sowohl die praktische Anwendbarkeit der Transformationen als auch eine deutliche Reduktion der Komplexität gegenüber anderen Lösungsansätzen. Einige der von uns vorgeschlagenen Verfahren unterbieten gar die Laufzeiten des meistgenutzten Elliptic Curve Digital Signature Algorithm (ECDSA) bei der Erstellung der Signaturen. Die Systematik der Lösung erlaubt prinzipiell auch die Transformation von Verfahren jenseits von IBS und ECC. Dadurch können auch Anwendungsfälle aus dem Bereich der Post-Quanten-Kryptographie von unseren Ergebnissen profitieren. Die vorliegende Arbeit liefert die nötigen Grundlagen für solche Erweiterungen, die aktuell diskutiert und entwickelt werden

A survey of the interaction between security protocols and transport services

This document provides a survey of commonly used or notable network security protocols, with a focus on how they interact and integrate with applications and transport protocols. Its goal is to supplement efforts to define and catalog Transport Services by describing the interfaces required to add security protocols. This survey is not limited to protocols developed within the scope or context of the IETF, and those included represent a superset of features a Transport Services system may need to support

Authentication in virtual private networks based on quantum key distribution methods

Quantum physics has a major influence on modern computer science and communications. New quantum-based solutions continue to be proposed by researchers. However, only a few techniques are possible to implement in practice. One of them is quantum key distribution, which ensures the confidentiality of digital data. This article introduces a new concept: quantum distribution of pre-shared keys. This approach provides end-users with very secure authentication, impossible to achieve using currently-available techniques. Secure authentication is a key requirement in virtual private networks (VPN)—popular protection in computer networks. The authors simulated quantum-based distribution of a shared secret in a typical VPN connection. Using a dedicated simulator, all individual steps of the quantum key distribution process were presented. Based on the created secret, a secure IPsec tunnel in a StrongSwan environment was established between AGH (Poland) and VSB (Czech Republic). It allows end-users to communicate at very high security levels.Web of Science7517107071069

L-band Digital Aeronautical Communications System (LDACS) draft-ietf-raw-ldacs-07

This document provides an overview of the architecture of the L-band Digital Aeronautical Communications System (LDACS), which provides a secure, scalable and spectrum efficient terrestrial data link for civil aviation. LDACS is a scheduled, reliable multi-application cellular broadband system with support for IPv6. LDACS shall provide a data link for IP network-based aircraft guidance. High reliability and availability for IP connectivity over LDACS are therefore essential

Deploying Virtual Machines on Shared Platforms

In this report, we describe mechanisms for secure deployment of virtual machines on shared platforms looking into a telecommunication cloud use case, which is also presented in this report. The architecture we present focuses on the security requirements of the major stakeholders’ part of the scenario we present. This report comprehensively covers all major security aspects including different security mechanisms and protocols, leveraging existing standards and state-of-the art wherever applicable. In particular, our architecture uses TCG technologies for trust establishment in the deployment of operator virtual machines on shared resource platforms. We also propose a novel procedure for securely launching and cryptographically binding a virtual machine to a target platform thereby protecting the operator virtual machine and its related credentials

L-band Digital Aeronautical Communications System (LDACS) draft-ietf-raw-ldacs-03

This document provides an overview of the architecture of the L-band Digital Aeronautical Communications System (LDACS), which provides a secure, scalable and spectrum efficient terrestrial data link for civil aviation. LDACS is a scheduled, reliable multi-application cellular broadband system with support for IPv6. LDACS shall provide a data link for IP network-based aircraft guidance. High reliability and availability for IP connectivity over LDACS are therefore essential

L-band Digital Aeronautical Communications System (LDACS) draft-maeurer-raw-ldacs-06

This document provides an overview of the architecture of the L-band Digital Aeronautical Communications System (LDACS), which provides a secure, scalable and spectrum efficient terrestrial data link for civil aviation. LDACS is a scheduled, reliable multi-application cellular broadband system with support for IPv6. LDACS shall provide a data link for IP network-based aircraft guidance. High reliability and availability for IP connectivity over LDACS are therefore essential

Post Quantum Design in SPDM for Device Authentication and Key Establishment

The Security Protocol and Data Model (SPDM) defines flows to authenticate hardware identity of a computing device. It also allows for establishing a secure session for confidential and integrity protected data communication between two devices. The present version of SPDM, namely version 1.2, relies on traditional asymmetric cryptographic algorithms that are known to be vulnerable to quantum attacks. This paper describes the means by which support for post-quantum (PQ) cryptography can be added to the SPDM protocol in order to enable SPDM for the upcoming world of quantum computing. We examine SPDM 1.2 protocol and discuss how to negotiate the use of post-quantum cryptography algorithms (PQC), how to support device identity reporting, means to authenticate the device, and how to establish a secure session when using PQC algorithms. We consider so called hybrid modes where both classical and PQC algorithms are used to achieve security properties as these modes are important during the transition period. We also share our experience with implementing PQ-SPDM and provide benchmarks for some of the winning NIST PQC algorithms

A Security Framework for Routing Protocols

With the rise in internet traffic surveillance and monitoring activities, the routing infrastructure has become an obvious target of attack as compromised routers can be used to stage large scale attacks. Routing protocols are also subjected to various threats such as capture and replay of packets that disclose the network information, forged routing control messages that may compromise a connection by deception, disruption of an on-going connection causing DoS attacks and spreading of unauthentic routing information in the network. Presently, strong cryptographic suites and key management mechanisms (IPsec and IKE) are available to secure host-to-host data communication but none of them focus on securing routing protocols. Today's routing protocols use a shared secret to perform mutual authentication and authorization, and depend on manual keying methods. For message integrity, they either rely on some built-in or external security feature that uses the same shared secret. The KARP working group of the IETF identified that the work is required to tighten the security of the routing protocols and demonstrated that automated key management solutions are needed for increasing security. Towards this goal we propose the RPsec framework. RPsec provides a common baseline for development of KMPs for the routing protocols, supports both automated and manual key management, and overcomes the weakness of existing manual key methods