1. A method comprising: while executing a first task, preparing a first request to perform an operation in an existing second task, wherein preparing the first request includes including in the first request a task port belonging to the first task; using an operating system kernel to transfer the first request to the second task; and while executing the second task: sending a second request from the second task to the trusted entity to determine whether the task port is valid, including requesting a process identifier associated with the task port using a system call of the operating system kernel and determining that the task port is valid if the operating system returns a process identifier for the task port identifier; sending a third request from the second task to the task port to identify a user that owns the task port, including sending a message to the task port requesting a user identifier associated with the task port, wherein the user identifier associated with the task port is the user identifier having receive rights to the task port; and performing the operation using the second task based on the identified user.