JustSTART: How to Find an RSA Authentication Bypass on Xilinx UltraScale(+) with Fuzzing

Fuzzing is a well-established technique in the software domain to uncover bugs and vulnerabilities. Yet, applications of fuzzing for security vulnerabilities in hardware systems are scarce, as principal reasons are requirements for design information access (HDL source code). Moreover, observation of internal hardware state during runtime is typically an ineffective information source, as its documentation is often not publicly available. In addition, such observation during runtime is also inefficient due to bandwidth-limited analysis interfaces (JTAG, and minimal introspection of internal modules). In this work, we investigate fuzzing for 7-Series and UltraScale(+) FPGA configuration engines, the control plane governing the (secure) bitstream configuration within the FPGA. Our goal is to examine the effectiveness of fuzzing to analyze and document the opaque inner workings of FPGA configuration engines, with a primary emphasis on identifying security vulnerabilities. Using only the publicly available chip and dispersed documentation, we first design and implement ConFuzz, an advanced FPGA configuration engine fuzzing and rapid prototyping framework. Based on our detailed understanding of the bitstream file format, we then systematically define 3 novel key fuzzing strategies for Xilinx configuration engines. Moreover, our strategies are executed through mutational structure-aware fuzzers and incorporate various novel custom-tailored, FPGA-specific optimizations. Our evaluation reveals previously undocumented behavior within the configuration engine, including critical findings such as system crashes leading to unresponsive states of the FPGA. In addition, our investigations not only lead to the rediscovery of the starbleed attack but also uncover JustSTART (CVE-2023-20570), capable of circumventing RSA authentication for Xilinx UltraScale(+). Note that we also discuss countermeasures

A Fixed-Latency Architecture to Secure GOOSE and Sampled Value Messages in Substation Systems

International Electrotechnical Commission (IEC) 62351-6 standard specifies the security mechanisms to protect real-time communications based on IEC 61850. Generic Object Oriented Substation Events (GOOSE) and Sampled Value (SV) messages must be generated, transmitted and processed in less than 3 ms, which challenges the introduction of IEC 62351-6. After evaluating the security threats to IEC 61850 communications and the state of the art in GOOSE and SV security, this work presents a novel architecture based on wire-speed processing able to provide message authentication and confidentiality. This architecture has been implemented and tested to evaluate its performance, resource usage, and the latency introduced. Other proposals in the scientific literature do not support real-time traffic, so they are not suitable for GOOSE and SV messages. Whereas the others exceed the target latency of 3 ms or do not comply with the standards, our design authenticates and encrypts real-time IEC 61850 data in less than 7 mu s-predictable latency-, and complies with IEC 62351:2020.This work was supported in part by the Ministerio de Economia y Competitividad of Spain under Project TEC2017-84011-R, in part by Fondo Europeo de Desarrollo Regional (FEDER) Funds through the Doctorados Industriales program under Grant DI-15-07857, and in part by the Department of Education, Linguistic Policy and Culture of the Basque Government through the Fund for Research Groups of the Basque University System under Grant IT978-16

An IoT Endpoint System-on-Chip for Secure and Energy-Efficient Near-Sensor Analytics

Near-sensor data analytics is a promising direction for IoT endpoints, as it minimizes energy spent on communication and reduces network load - but it also poses security concerns, as valuable data is stored or sent over the network at various stages of the analytics pipeline. Using encryption to protect sensitive data at the boundary of the on-chip analytics engine is a way to address data security issues. To cope with the combined workload of analytics and encryption in a tight power envelope, we propose Fulmine, a System-on-Chip based on a tightly-coupled multi-core cluster augmented with specialized blocks for compute-intensive data processing and encryption functions, supporting software programmability for regular computing tasks. The Fulmine SoC, fabricated in 65nm technology, consumes less than 20mW on average at 0.8V achieving an efficiency of up to 70pJ/B in encryption, 50pJ/px in convolution, or up to 25MIPS/mW in software. As a strong argument for real-life flexible application of our platform, we show experimental results for three secure analytics use cases: secure autonomous aerial surveillance with a state-of-the-art deep CNN consuming 3.16pJ per equivalent RISC op; local CNN-based face detection with secured remote recognition in 5.74pJ/op; and seizure detection with encrypted data collection from EEG within 12.7pJ/op.Comment: 15 pages, 12 figures, accepted for publication to the IEEE Transactions on Circuits and Systems - I: Regular Paper

Tree Parity Machine Rekeying Architectures

The necessity to secure the communication between hardware components in embedded systems becomes increasingly important with regard to the secrecy of data and particularly its commercial use. We suggest a low-cost (i.e. small logic-area) solution for flexible security levels and short key lifetimes. The basis is an approach for symmetric key exchange using the synchronisation of Tree Parity Machines. Fast successive key generation enables a key exchange within a few milliseconds, given realistic communication channels with a limited bandwidth. For demonstration we evaluate characteristics of a standard-cell ASIC design realisation as IP-core in 0.18-micrometer CMOS-technology

Side-Channel Attacks and Countermeasures for the MK-3 Authenticated Encryption Scheme

In the field of cryptography, the focus is often placed on security in a mathematical or information-theoretic sense; for example, cipher security is typically evaluated by the difficulty of deducing the plaintext from the ciphertext without knowledge of the key. However, once these cryptographic schemes are implemented in electronic devices, another class of attack presents itself. Side-channel attacks take advantage of the side effects of performing a computation, such as power consumption or electromagnetic emissions, to extract information outside of normal means. In particular, these side-channels can reveal parts of the internal state of a computation. This is important because intermediate values occurring during computation are typically considered implementation details, invisible to a potential attacker. If this information is revealed, then the assumptions of a non-side-channel-aware security analysis based only on inputs and outputs will no longer hold, potentially enabling an attack. This work tests the effectiveness of power-based side-channel attacks against MK-3, a customizable authenticated encryption scheme developed in a collaboration between RIT and L3Harris Technologies. Using an FPGA platform, Correlation Power Analysis (CPA) is performed on several different implementations of the algorithm to evaluate their resistance to power side-channel attacks. This method does not allow the key to be recovered directly; instead, an equivalent 512-bit intermediate state value is targeted. By applying two sequential stages of analysis, a total of between 216 and 322 bits are recovered, dependent on customization parameters. If a 128-bit key is used, then this technique has no benefit to an attacker over brute-forcing the key itself; however, in the case of a 256-bit key, CPA may provide up to a 66-bit advantage. In order to completely defend MK-3 against this type of attack, several potential countermeasures are discussed at the implementation, design, and overall system levels