Early thinking was in terms of capability handles. As with file descriptors, the handle is only meaningful when passed across a protection boundary to something which can check if the handle is valid.
Later, there were encrypted capabilities, which are signed data, like TLS certs.
These get kind of bulky. And hardware support, in a few machines.
Later, there were encrypted capabilities, which are signed data, like TLS certs. These get kind of bulky. And hardware support, in a few machines.