Processing DNA Storage through Programmable Assembly in a Droplet‐Based Fluidics System

Abstract DNA can be used to store digital data, and synthetic short‐sequence DNA pools are developed to store high quantities of digital data. However, synthetic DNA data cannot be actively processed in DNA pools. An active DNA data editing process is developed using splint ligation in a droplet‐controlled fluidics (DCF) system. DNA fragments of discrete sizes (100–500 bps) are synthesized for droplet assembly, and programmed sequence information exchange occurred. The encoded DNA sequences are processed in series and parallel to synthesize the determined DNA pools, enabling random access using polymerase chain reaction amplification. The sequencing results of the assembled DNA data pools can be orderly aligned for decoding and have high fidelity through address primer scanning. Furthermore, eight 90 bps DNA pools with pixel information (png: 0.27–0.28 kB), encoded by codons, are synthesized to create eight 270 bps DNA pools with an animation movie chip file (mp4: 12 kB) in the DCF system

Kernel Code Integrity Protection at the Physical Address Level on RISC-V

An operating system kernel has the highest privilege in most computer systems, making its code integrity critical to the entire system’s security. Failure to protect the kernel code integrity allows an attacker to modify the kernel code pages directly or trick the kernel into executing instructions stored outside the kernel code pages. Existing prevention mechanisms rely on the memory management unit in which certain memory pages are marked as not-executable in supervisor mode to prevent such attacks. However, an attacker can bypass these existing mechanisms by directly manipulating the page table contents to mark the memory pages with malicious code as supervisor-executable. This paper shows that a small architectural extension enables a physical address-level mechanism to stop this threat without relying on page table integrity. PRIV LOCK lets, at boot time, the kernel specifies the physical address ranges containing its code. At run time, PRIV LOCK ensures that the content within the range is not manipulated and that only the instructions from those pages are executed while the processor runs in supervisor mode. Despite this protection, the kernel can still create new code pages (e.g., for loadable kernel modules) and make them executable with the help of PRIV LOCK ’s secure loader. The experimental results show that PRIV LOCK incurs low performance (<0.5%), area (0.14–0.3%), and energy/power (0.053–2%) overhead