Cryptographic Hardware and Embedded Systems - CHES 2004

Applications, Optimization, and Advanced Design

INTRODUCTION The immense growth of portable and mobile systems (smart phones, tablets, netbooks) and the increasing integration of computational logic into any devices through initiatives like future Internet and Internet of things have led to a flourish in embedded system technology stemming the creativity of the IT market to new levels. Wireless, mobile and portable devices are gradually replacing many traditional computer systems due to the increasing user need for mobility in high-end technology

Smart Card Research and …, 2008

This paper introduces the Trusted Execution Module (TEM); a high-level specification for a commodity chip that can execute user-supplied procedures in a trusted environment. The TEM is capable of securely executing partially encrypted procedures/closures expressing arbitrary computation. These closures can be generated by any (potentially untrusted) party who knows the TEM’s public encryption key. Compared to a conventional smartcard, which is typically used by pre-programming a limited set of domain- or application- specific commands onto the smartcard, and compared to the Trusted Platform Module (TPM), which is limited to a fixed set of cryptographic functions that cannot be combined to provide general-purpose trusted computing, the TEM is significantly more flexible. Yet we present a working implementation using existing inexpensive Javacard smartcards that does not require any export-restricted technology. The TEM’s design enables a new style of programming, which in turn enables new applications. We show that the TEM’s guarantees of secure execution enable exciting applications that include, but are not limited to, mobile agents, peer-to-peer multiplayer online games, and anonymous offline payments.

2009

Security issues become more and more important during the development of mobile devices. In this paper we propose a thorough overview of processor-based solutions to protect programs and data exchanges within embedded systems. A discussion about the limitations of existing solutions is provided and new directions are proposed.

Microprocessors and Microsystems, 2009

With current trends toward embedded computer systems' ubiquitous accessibility, connectivity, diversification, and proliferation, security becomes a critical issue in embedded computer systems design and operation. Embedded computer systems are subjected to ...

Proceedings of the Network …, 2012

Remote attestation is the process of securely verifying internal state of a remote hardware platform. It can be achieved either statically (at boot time) or dynamically, at run-time in order to establish a dynamic root of trust. The latter allows full isolation of a code region from preexisting software (including the operating system) and guarantees untampered execution of this code. Despite the untrusted state of the overall platform, a dynamic root of trust facilitates execution of critical code. Prior software-based techniques lack concrete security guarantees, while hardware-based approaches involve security co-processors that are too costly for low-end embedded devices.

2002

A Physical Unknown Function (PUF) is a function that is easy to evaluate but hard to characterize. We introduce controlled physical unknown functions (CPUFs) which are PUFs that can only be accessed via an algorithm that is physically bound to the PUF in an inseparable way. Controlled PUFs enable several applications including certified execution, where a certificate is produced that proves that a specific computation was carried out on a specific processor. Certified execution has many benefits, including protection against malicious volunteers/entities in grid computing, anonymous computing and other forms of distributed computation. An integrated circuit (IC) containing a controlled PUF can be authenticated using challenge-response pairs (CRP's). We describe protocols for CRP management that protect against a man-in-the-middle attack. We also describe protocols through which controlled PUF's can be used in the applications of smartcard identification and certified execution, and briefly discuss a software licensing application.

Hack. in 2009, 2009

Lecture Notes in Computer Science, 2006

Amongst areas of cryptographic research, there has recently been a widening interest for code-based cryptosystems and their implementations. Besides the a priori resistance to quantum computer attacks, they represent a real alternative to the currently used cryptographic schemes. In this paper we consider the implementation of the Stern authentication scheme and one recent variation of this scheme by Aguilar et al.. These two schemes allow public authentication and public signature with public and private keys of only a few hundreds bits. The contributions of this paper are twofold: first, we describe how to implement a code-based signature in a constrained device through the Fiat-Shamir paradigm, in particular we show how to deal with long signatures. Second, we implement and explain new improvements for code-based zero-knowledge signature schemes. We describe implementations for these signature and authentication schemes, secured against side channel attacks, which drastically improve the previous implementation presented at Cardis 2008 by Cayrel et al.. We obtain a factor 3 reduction of speed and a factor of about 2 for the length of the signature. We also provide an extensive comparison with RSA signatures.

arXiv (Cornell University), 2019

Modern society is increasingly surrounded by, and is growing accustomed to, a wide range of Cyber-Physical Systems (CPS), Internet-of-Things (IoT), and smart devices. They often perform safety-critical functions, e.g., personal medical devices, automotive CPS as well as industrial and residential automation (e.g., sensor-alarm combinations). On the lower end of the scale, these devices are small, cheap and specialized sensors and/or actuators. They tend to be equipped with small anemic CPU, have small amounts of memory and run simple software. If such devices are left unprotected, consequences of forged sensor readings or ignored actuation commands can be catastrophic, particularly, in safety-critical settings. This prompts the following three questions: (1) How to trust data produced, or verify that commads were performed, by a simple remote embedded device?, (2) How to bind these actions/results to the execution of expected software? and, (3) Can (1) and (2) be attained even if all software on a device could be modified and/or compromised? In this paper we answer these questions by designing, showing security of, and formally verifying, VAPE: Verified Architecture for Proofs of Execution. To the best of our knowledge, this is the first of its kind result for low-end embedded systems. Our work has a range of applications, especially, to authenticated sensing and trustworthy actuation, which are increasingly relevant in the context of safety-critical systems. VAPE architecture is publicly available and our evaluation indicates that it incurs low overhead, affordable even for very low-end embedded devices, e.g., those based on TI MSP430 or AVR ATmega processors.