Browse Prior Art Database

Data Security in NVDIMM

IP.com Disclosure Number: IPCOM000246467D
Publication Date: 2016-Jun-09
Document File: 5 page(s) / 112K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method in the area of non-volatile DIMM module, which proposes a security feature to ensure non-availability of useful DRAM and/or flash data, when module is removed in an unauthorized manner.

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Data Security in NVDIMM

Non-volatile DIMM (NVDIMM) incorporates DRAM, Flash, control logic, and an independent power source to retain critical in-memory data through unexpected power loss events, system crashes, or planned shutdowns. During normal operation, the NVDIMM appears to the host system as a standard DRAM memory module, providing the speed, latency, and endurance benefits of DRAM. In the event of an unexpected power loss or system crash, the critical data residing in the DRAM is saved to Flash.

    In NVDIMM, upon system power loss, an Asynchronous DRAM Refresh (ADR) sequence will be triggered. A hardware interrupt to the memory controller which will flush the write-protected data buffers and place the DRAM in self-refresh. This process is critical during a power loss event or system crash to ensure the data is in a "safe" state when the NVDIMM takes control of the DRAM to backup to Flash. ADR will flush the write-protected data buffers in the memory controller and place the DRAM in self-refresh. When ADR is complete, the SAVE# pin is triggered. The NVDIMM will then take control of the DRAM and move the contents to Flash. When the transfer is complete, the NVDIMM goes into a zero power state.

    Data persistency is a useful and intended function of an NVDIMM module. However, if a module is removed in an unauthorized manner (Ex: in data centers), data residing in Flash can be hacked which provides a security hole (if not protected otherwise). Specifically in the context of

NVDIMM, unauthorized plug-out triggers data backup process using "super capacitor" and data will be backed to flash memory.

    The proposed method in the area of NVDIMM flash-based enables a security feature to ensure non-availability of useful DRAM and/or flash data, when module is removed in an unauthorized manner. System supplies security signal (security) to NVDIMM controller:


When NVDIMM is set to operate in security mode, assertion (active high) indicates

NVDIMM module...