Security analysis on memory ICs

Abstract

Static Random-Access Memory (SRAM) has been widely applied in electronic devices to generate and store sensitive information such as secret key and password for hardware security applications. The SRAM is believed to be more secure than any other storage devices because of its volatile properties where the stored information will be lost when the SRAM is powered-off. However, data imprinting effect has been proven by many researchers using different approaches that the data was retained in the memory cells even after turned-off for a long period. This effect is considered as one of the major security concerns where the sensitive data could be recovered by attackers. An experiment was implemented by storing an 8-bits grayscale image into the 3 commercial SRAM chips from different manufacturers, i.e. Amic, Lyontek, Cypress, followed by stressing it in high voltage and high temperature environment for 40 hours. The vulnerability of the SRAM chips is evaluated by comparing the initial power-on data and the final power-on data after 40 stressing hours. Based on the measurement results, the original image cannot be recovered for all 3 SRAM chips. However, a positive trend is observed in Amic’s SRAM chip where more information could be possibly revealed with longer stressing hours.