Biblio

Dynamic Random Access Memory (DRAM) is widely used for data storage and, when a computer system is in operation, the DRAM can contain sensitive information such as passwords and cryptographic keys. Therefore, the DRAM is a prime target for hardware-based cryptanalytic attacks. These attacks can be performed in the supply chain to capture default key mechanisms enabling a later cyber attack or predisposition the system to remote effects. Two prominent attack classes against memory are the Cold Boot attack which recovers the data from the DRAM even after a supposed power-down and Rowhammer attack which violates memory integrity by influencing the stored bits to flip. In this paper, we propose an on-chip technique that obfuscates the memory addresses and data and provides a fast detect-response to defend against these hardware-based security attacks on DRAM. We advance the prior hardware security research by making two contributions. First, the key material is detected and erased before the Cold Boot attacker can extract the memory data. Second, our solution is on-chip and does not require nor depend on additional hardware or software which are open to additional supply chain attack vectors. We analyze the efficacy of our scheme through circuit simulation and compare the results to the previous mitigation approaches based on DRAM write operations. Our simulation and analysis results show that purging key information used for address and data randomization can be achieved much faster and with lower power than with typical DRAM write techniques used for sanitizing memory content. We demonstrate through circuit simulation of the key register design a technique that clears key information within 2.4ns which is faster by more than two orders magnitude compared to typical DRAM write operations for 180nm technology, and with a power consumption of 0.15 picoWatts.

Distributed banking platforms and services forgo centralized banks to process financial transactions. For example, M-Pesa provides distributed banking service in the developing regions so that the people without a bank account can deposit, withdraw, or transfer money. The current distributed banking systems lack the transparency in monitoring and tracking of distributed banking transactions and thus do not support auditing of distributed banking transactions for accountability. To address this issue, this paper proposes a blockchain-based distributed banking (BDB) scheme, which uses blockchain technology to leverage its built-in properties to record and track immutable transactions. BDB supports distributed financial transaction processing but is significantly different from cryptocurrencies in its design properties, simplicity, and computational efficiency. We implement a prototype of BDB using smart contract and conduct experiments to show BDB's effectiveness and performance. We further compare our prototype with the Ethereum cryptocurrency to highlight the fundamental differences and demonstrate the BDB's superior computational efficiency.