EXECUTION PROTECTION USING DATA COLOURING

The present invention relates to an execution system having at least a central processing unit (CPU), system memory (SM) and a secure agent component (SAC) monitoring memory access instructions occurring between the central processing unit (CPU) and system memory (SM), said secure agent component (SAC) comprising a colour memory (CM) storing a colour tag for each memory address of the system memory (SM):said secure agent component (SAC) being such that, for store instruction at a destination address, it copies the colour tag stored at the instruction address in the colour memory to the destination address in the colour memory (CM) while storing data,said secure agent component (SAC) being further such that, for load instruction at a retrieval address, it compares the colour tag stored at the retrieval address and the colour tag at the load instruction in the colour memory (CM),dysfunction is detected if colour tags are different.