Search

Verifying the integrity of embedded device characteristics is required to ensure secure operation of a device. One central challenge is to securely extract and store device-specific configurations for future verification. Existing device attestation schemes suffer from notable limitations, including a lack of standardization and a failure to encompass all hardware and software aspects inherent to a platform. This paper proposes an extension of the NSA Cybersecurity Directorate's Platform Attribute Certificate Creator (PACCOR) for the ESP32, a widely-used microcontroller series. Platform Attribute Certificates store device characteristics as per the Trusted Computing Group's Platform Certificate Profile. As of today, there is little research on hybrid attestation schemes utilizing Platform Attribute Certificates on embedded devices, which this work addresses. This paper presents a collection of attacks that can be detected using PACCOR4ESP. The toolkit extracts security-relevant information from an ESP32-S3, such as the firmware hash, bootloader hash, GPIO pin configuration, and a reference to the endorsement key of the secure element, and automatically embeds it into a Platform Attribute Certificate. Lastly, this work shows how PACCOR4ESP can be integrated with existing embedded device attestation frameworks, such as RAS, CRAFT, and SEDA.

Smart contracts on a blockchain behave precisely as specified by their code. A vulnerability in this code can lead to unexpected behaviour, which is hard to fix because a blockchain does not allow to change smart contract code after its deployment. Such vulnerabilities have led to several incidents. In the aftermath of such an event, a hard-fork between Ethereum and Ethereum classic was the result. This thesis proposes to develop a new smart contract programming language with the primary focus on safety, auditability, and the intention to prevent as many of the known categories of vulnerabilities by design as possible. The programming language's code is validated during deployment and afterwards isolated from other smart contracts running on the same blockchain to enforce compile-time guarantees during runtime. The designed programming language does evaluate new concepts and paradigms rarely used in non-smart contract environments for their potential benefit in a smart contract environment.

We present an algorithm for the Merkle tree traversal problem which combines the efficient space-time trade-off from the fractal Merkle tree [3] and the space efficiency from the improved log space-time Merkle trees traversal [8]. We give an exhaustive analysis of the space and time efficiency of our algorithm in function of the parameters H (the height of the Merkle tree) and h (h = H L where L is the number of levels in the Merkle tree). We also analyze the space impact when a continuous deterministic pseudo-random number generator (PRNG) is used to generate the leaves. We further program a low storage-space and a low time-overhead version of the algorithm in Java and measure its performance with respect to the two different implementations cited above. Our implementation uses the least space when a continuous PRNG is used for the leaf calculation., Comment: 19 pages, 6 figures, 2 tables