Nowadays, it is very common to share a computer with others, especially if you do computation in the cloud or even on your own mobile device

said senior author Mengjia Yan. "Through these shared resources, an attacker can seek out even very fine-grained information"

There are several ways a malicious program can target shared memory to access sensitive information

The team focused on a solution to foil contention attacks—when the malicious program tries to access memory hardware at the same time as another program.

"The attacker is poking at the memory controller, the library door, to say, 'is it busy now?'" said co-author Joel Emer. "If they get blocked because the library door is opening already

because the victim program is already using the memory controller—they are going to get delayed.

The researchers developed a scheme that uses a graph structure, known as a directed acyclic graph, or DAG, to process requests and submit the requests to the memory controller on a fixed schedule

The structure allows memory hardware to be shared among programs securely. The team named the security scheme DAGguise.