Control flow integrity to prevent potential leakage of sensitive data to adversaries

A method comprising:

• detecting, in computer program code, an indirect branch to call one of a plurality of functions using a first register;
• augmenting the computer program code to store an identifier of the indirect branch call in a second register;
• and
• augmenting the code for each function to:
• determine whether an identifier for the function matches the identifier stored in the second register;
• and
• render the first register unusable if the identifier for the function does not match the identifier stored in the second register.

A system comprising:

• means to detect, in computer program code, an indirect branch to call one of a plurality of functions using a first register;
• means to augment the computer program code to store an identifier of the indirect branch call in a second register;
• and
• means to augment the code for each function to:
• determine whether an identifier for the function matches the identifier stored in the second register;
• and
• render the first register unusable if the identifier for the function does not match the identifier stored in the second register.