Watermarked ReRAM: A Technique to Prevent Counterfeit Memory Chips

Approximate MRAM: High-performance and Power-efficient Computing with MRAM Chips for Error-tolerant Applications

“…Our proposed technique conceals information in the write (set/reset) time of ReRAM bit cells. The set and reset time increases monotonically with stress levels, making it possible to retain a hidden message and retrieve it through a proper threshold value that separates the stressed and fresh memory cells [8]. The authorized entity performs the proposed information concealing technique in the memory to encode secret information in ReRAM.…”

“…Each switching operation gradually degrades the resistance of HRS, which is permanent and, thus, cannot be reversed. However, the number of repeated switching cycles, N , used to encode the secret message is determined empirically through cell characterization for given memory chips to ensure proper separation without causing excessive stress [8]. From an encoding perspective, minimizing N is desirable because the encoding time of the secret message is directly proportional to the number of switching cycles.…”

“…We hide the secret message in analog physical characteristics of ReRAM by repeatedly stressing the memory cells. To this end, first, we characterize a few memory cells to understand the analog physical characteristics of ReRAM cells at different stressing levels up to the maximum endurance [8]. Later, the authorized personnel performs the retrieval operation to extract the hidden message bits from the analog physical characteristics through standard digital interfaces when required.…”

“…Our proposed technique can be easily implemented on commercial off-the-shelf (COTS) ReRAM chips, enabling secure and covert data storage. The advantage of the information hiding technique is -(i) the hidden data can not be retrieved due to watermarking if the storage device is lost or stolen [8], and (ii) the attacker can not read or copy the ciphertext, ensuring an additional protection layer over a typical encryption engine.…”

“…Note that our prior work [8] focuses only on watermarking, a traditional application of information hiding, to prevent piracy. Compared to [8], this version presents the information concealing technique, enabling several interesting applications other than watermarking, such as secure and covert data storage, data integrity, and covert communication [1]. The key contributions of this article are as follows.…”