Address masking between users

A method, comprising:

• assigning a first mask value to a first user of a computing system and a second mask value to a second user of the computing system, the first mask value and the second mask value being unique to one another;
• while executing a first instruction on behalf of the first user, applying the first mask value to set selection bits in a memory address accessed by the first instruction;
• and
• while executing a second instruction on behalf of the second user, applying the second mask value to set selection bits in a memory address accessed by the second instruction;
• whereby memory addressing maps differently for the first user and the second user to reduce risk of a timing attack by any user on another user;
• wherein only a portion of each memory address of the memory addresses is masked.

A computer-readable medium storing a software program that, when executed by a processor, causes the processor to:

• assign a first mask value to a first user of a computing system and a second mask value to a second user of the computing system, the first mask value and the second mask value being unique to one another;
• while executing a first instruction on behalf of the first user, apply the first mask value to set selection bits in a memory address accessed by the first instruction;
• and
• while executing a second instruction on behalf of the second user, applying the second mask value to set selection bits in a memory address accessed by the second instruction;
• whereby memory addressing maps differently for the first user and the second user;
• wherein only a portion of each memory address of the memory addresses is masked.