Abstract: A method for secure communications between a transmitting computer and a receiving computer includes transmitting data from the transmitting computer over a first one-way link to a data security engine, receiving and validating the data within the data security engine, and, after validating the data, transmitting the data from the data security engine to the receiving computer over a second one-way link.

Abstract: One exemplary embodiment involves receiving, at a server, a request for a document key for accessing a document on a client device, wherein the request comprises an identity of an access policy and information about the document. The exemplary method further comprises determining, at the server, whether access to the document is permitted according to the access policy. If access to the document is permitted, the exemplary method involves computing, at the server, the document key using the information about the document, wherein the document key is document specific, wherein, prior to the computing of the document key, the document key is not stored for access by the server. The exemplary method further involves responding to the request by providing the document key for use in accessing the document on the client device.

Abstract: Provided is a method where a power management apparatus (a) acquires, from a server managed by a manufacturer of an electronic appliance, a public key paired with a secret key that the electronic appliance and the server hold, (b) generates a ciphertext by generating a random number and encrypting the random number by the public key, and (c) transmits the ciphertext to the electronic appliance and the server, where the electronic appliance (d) restores the random number by decrypting the ciphertext transmitted in (c), (e) causes an electrical part to operate, based on the random number, and (f) transmits to the server the value of current flowing through the electrical part, and where the server (g) restores the random number by decrypting the ciphertext transmitted in (c), (h) calculates the value of current to flow through the electrical part based on the random number, and (i) compares values of current.