To increase the safety of quantum key delivery and increase a key delivery rate while avoiding a remarkable drop of the safety even when a plurality of photons are mixed into a unit time slot.
The common private encryption key delivery system between signal reception and transmission sides includes a generation means for generating a photon pair ab formed from two photons a, b prepared in such an initial state F as to have a maximum quantum mechanics correlation with respect to an internal or external freedom, a holding means for holding the output photon a for a time ΔT, an encoding means for converting the state of the photon pair ab to a state m1 or m2 different in the weakened degree of the quantum correlation according to 1 or 0 of an encode target key information bit by operating the state of the accepted photon b and then returning the photon b to the reception side, and a decoding means for determining the state m1 or m2 of the photon pair ab by causing two-photon interference between the photon a and the returned photon b. The reception side has the photon pair generating means, the holding means and the decoding means. The reception side does not emit the photon a to the outside.
COPYRIGHT: (C)2010,JPO&INPIT
TAKEI HIROKI
| JP2002164883A | 2002-06-07 | |||
| JP2007318445A | 2007-12-06 |
JPN6012038053; 清水 薫， 武居 弘樹， 玉木 潔: '光子ペアの非最大エンタングルド状態を利用した量子鍵配送' 日本物理学会講演概要集 Ｖｏｌ． ６４， Ｎｏ． １, 200903, ｐ． １８１, ［ｏｎｌｉｎｅ］
JPN6012038051; 清水 薫， 玉木 潔， 深坂 紘行: 'ＥＰＲペア中の一粒子の往復伝送による量子稠密鍵配送' 第１９回量子情報技術研究会資料 , 200811, ｐｐ． １２-１７
Atsuhiro Hamanaka
Next Patent: SOLID-STATE IMAGING DEVICE