Final answer:
Rights amplification in Multics allowed a process to obtain higher privileges via a hierarchical 'ring mechanism.'
Step-by-step explanation:
Rights amplification in Multics (Multiplexed Information and Computing Service), which was a pioneering operating system developed in the 1960s, refers to the mechanism that allows a process running with certain privileges to obtain more privileges than those with which it started.
This feature was integral to the Multics security model, which sought to provide fine-grained control over who could do what within the system. The main means of rights amplification in Multics was through the use of a 'ring mechanism', which was a hierarchical protection system that consisted of different levels (rings) with varying degrees of privilege.
A process could be granted more rights by moving it to a more privileged ring under controlled conditions. For example, a user program running in a less privileged ring could call a highly privileged supervisor function residing in an inner ring, which then executes with the privileges of that inner ring to perform certain operations that the user program would not be able to do directly.
Properly designed, this allowed for controlled elevation of privileges, a concept that is still relevant in modern security practice. Two important aspects of this rights amplification process were the ring bracket mechanism and the gate mechanism, which together enforced the controlled transfer of execution and the associated privilege change.
A less privileged program could access more privileged functions using controlled conditions, such as ring brackets and gate mechanisms.