| Patent application number | Description | Published |
|---|
| 20080240734 | Multimode Optical Transmission Device - An optical transmitting circuit ( | 10-02-2008 |
| 20080247547 | Data transmitting apparatus and data receiving apparatus - A data communication apparatus which improves security against eavesdropping is provided for secret communication using Y-00 protocol. In a data transmitting apparatus | 10-09-2008 |
| 20080310857 | OPTICAL SPACE TRANSMISSION METHOD AND OPTICAL SPACE TRANSMISSION APPARATUS - An optical identification signal generation section electrical-to-optical-converts and emits identification information. A modulation section modulates information data in a predetermined modulation type determined from the identification information. An optical data signal generation section electrical-to-optical-converts and emits the modulated information data. A two-dimensional optical-to-electrical conversion section receives the optical identification signal and acquires screen information including an image of the optical identification signal. An information reading section reads predetermined pixel information from the screen information and reproduces the identification information. An optical-to-electrical conversion section optical-to-electrical-converts the optical data signal. A demodulation section demodulates the information data in the predetermined demodulation type determined from the identification information, and reproduces the information data. A screen display section displays and updates the screen information, and displays the content of the information data in a predetermined manner from the identification information. | 12-18-2008 |
| 20090009259 | ANGLE MODULATOR - An angle modulator having an excellent noise characteristic and an excellent distortion characteristic independent of an unwanted wave component of an optical modulation signal is provided. The angle modulator ( | 01-08-2009 |
| 20090103721 | DATA TRANSMITTING APPARATUS, DATA RECEIVING APPARATUS AND DATA COMMUNICATION APPARATUS - Provided is a data communication apparatus which is highly concealable and significantly increases time necessary for an eavesdropper to analyze cipher text. A multi-level code generation section ( | 04-23-2009 |
| 20090175631 | Pulse signal demodulation device - In an optical transmission system in which a pulse signal is converted into an optical signal before transmission, a pulse signal demodulation device capable of correctly demodulating the pulse signal is provided. An optical-to-electrical conversion section ( | 07-09-2009 |
| 20090323852 | DATA RECEIVING APPARATUS - To provide a receiving apparatus which is capable of demodulating information data from a multi-level modulated signal, which is generated by using a Y-00 protocol, without using high-performance component parts. In the receiving apparatus, the soft decision section | 12-31-2009 |
| 20090323955 | DATA TRANSMITTING APPARATUS AND DATA RECEIVING APPARATUS - In secret communication using a Y-00 protocol, provided is a data communication apparatus which realizes reduction in a random number generation speed by using a plurality of random number generators, and which also ensures security. The data communication apparatus includes: a plurality of random number generation sections | 12-31-2009 |
| 20100158249 | DATA TRANSMITTING APPARATUS AND DATA RECEIVING APPARATUS - Provided is a data communication apparatus which significantly increases time necessary for an eavesdropper to analyze cipher text and which is superior in concealability based on astronomical computational complexity. A multi-level signal, which is generated by using data and key information, has a minor amplitude modulation, which is based on a random number signal generated on a transmission side, overlapped thereon, and is then transmitted. On a receiving side, instead of data decision, three types of decision, i.e., “1”, “0” and “decision impossible”, are performed on a random number signal by using two threshold values whose interval is significantly wider than a modulation amplitude based on random numbers. Information of a bit whose decision is performed successively is returned to the transmission side, and the bit is used commonly as a new key. Accordingly, in a single transmitting/receiving apparatus, cipher text transmission and key distribution can be realized simultaneously. | 06-24-2010 |
| 20100266124 | DATA COMMUNICATION APPARATUS - A data communication apparatus wherein the stealthiness has been enhanced by significantly increasing the time required for a wiretapper to decrypt an encrypted text. The data communication apparatus is constituted by connecting a data transmitting apparatus and a data receiving apparatus via a transmission path. The data transmitting apparatus receives a first predetermined initial value (key information) and information data, generates a multi-valued signal the level of which varies substantially like a random number, and converts the multi-valued signal to a modulated signal of a predetermined modulation format for transmission. The data receiving apparatus demodulates the modulated signal to output the multi-valued signal, and then reproduces the information data from the multi-valued signal and a second predetermined initial value (key information) that is received. | 10-21-2010 |
| 20100303234 | DATA COMMUNICATION APPARATUS - A data communication apparatus wherein the stealthiness has been enhanced by significantly increasing the time required for a wiretapper to decrypt an encrypted text. The data communication apparatus is constituted by connecting a data transmitting apparatus and a data receiving apparatus via a transmission path. The data transmitting apparatus receives a first predetermined initial value (key information) and information data, generates a multi-valued signal the level of which varies substantially like a random number, and converts the multi-valued signal to a modulated signal of a predetermined modulation format for transmission. The data receiving apparatus demodulates the modulated signal to output the multi-valued signal, and then reproduces the information data from the multi-valued signal and a second predetermined initial value (key information) that is received. | 12-02-2010 |
| 20110085804 | MULTIMODE OPTICAL TRANSMISSION DEVICE - An optical transmitting circuit ( | 04-14-2011 |
