Abstract: Trusted nodes in a network perform secure out-of-band symmetric encryption key delivery to user devices. A first trusted node receives a request from a first user device to deliver symmetric encryption keys to the first user device and a second user device, as a pair of user devices. The first trusted node delivers a second symmetric encryption key to the second user device, via trusted nodes. The first trusted node receives confirmation of delivery of the second symmetric encryption key. Responsive to the confirmation of delivery, the first trusted node delivers the first symmetric encryption key to the first user device.

Abstract: A trusted node, for quantum key distribution, has a quantum key engine, a quantum key controller and a trusted node controller. The quantum key engine exchanges quantum keys. The quantum key controller directs encryption and decryption. The trusted node controller directs the quantum key controller and the quantum key engine, and has no direct access to keys and data protected by the system, including unencrypted quantum keys.

Abstract: A trusted node, for quantum key distribution, has a quantum key engine, a quantum key controller and a trusted node controller. The quantum key engine exchanges quantum keys. The quantum key controller directs encryption and decryption. The trusted node controller directs the quantum key controller and the quantum key engine, and has no direct access to keys and data protected by the system, including unencrypted quantum keys.

Abstract: Trusted nodes in a network perform secure out-of-band symmetric encryption key delivery to user devices. A first trusted node receives a request from a first user device to deliver symmetric encryption keys to the first user device and a second user device, as a pair of user devices. The first trusted node delivers a second symmetric encryption key to the second user device, via trusted nodes. The first trusted node receives confirmation of delivery of the second symmetric encryption key. Responsive to the confirmation of delivery, the first trusted node delivers the first symmetric encryption key to the first user device.

Abstract: In a game having magnetically operable pieces (3) there are below a game board (2) several operating devices (4) for operating the pieces, these operating devices being separated by intermediate layers (7) that are parallel to the game board. The intermediate layers are thin and easily flexible and rest on top of each other, the game board resting on top of the top intermediate layer. A specially designed piece is included in the game, intended for contact with the game board. This piece has two supports (9, 10) e.g. the feet of a human figure. One (9) of the supports rests on and carries a magnet (8) that can be moved by a cooperating magnet (13) beneath the game board. The other support (10) has a supporting surface (11) of friction material.

Abstract: In a game having magnetically operable pieces (3) there are below a game board (2) several operating magnets (4) for operating the pieces, the operating magnets being separated by intermediate layers (7) that are parallel to the game board. The intermediate layers are thin and easily flexible and rest on top of each other, the game board resting on top of the top intermediate layer. A specially designed piece is included in the game.

Abstract: A rebound apparatus for practicing striking a ball with a racket. The apparatus has an elongated rectangular frame which is mounted on a base for pivotal adjustment about a horizontal axis. Mounted on the frame is a flexible material which is relatively loose along the width of the frame and relatively taut along the length of the frame. The upper end of the frame is curved out of the plane of the main portion of the frame, and this upper end supports a ball rebound surface. The flexible material may be secured at its upper end to the rebound surface. The length of the frame is adjustable. In use, a ball when hit by a racket will strike the flexible material, rebound upwardly against the ball rebound surface, and then rebound again in a direction back toward the player who hit the ball.