Optical encryption and decryption method and system
US6907124B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 16, 1999 |
| Grant date | Jun 14, 2005 |
| Priority date | — |
| Expiry date | Jun 16, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/46
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The invention relates to securing of information utilising optical imaging technologies and more specifically to phase encryption and decryption of images. An image is encrypted into a mask having a plurality of mask resolution elements (Xm, Ym) by encoding the image using e.g. a phase mask with an encoded phase value φ (Xm, Ym) and an encoded amplitude value a (Xm, Ym), and by further encrypting the mask (using e.g. a spatial light modulator) by addition of an encrypting phase value φc (Xm, Ym) to the encoded phase value φ (Xm, Ym) and by multiplication of an encrypting amplitude value ac (Xm, Ym) with the encoded phase value a (Xm, Ym). The method of decrypting comprises the steps of decrypting the mask by radiating electromagnetic radiation towards the mask and inserting into the path of the electromagnetic radiation a complex spatial electromagnetic radiation modulator comprising modulator resolution elements, the decrypting phase value φd (Xd, Yd) and the decrypting amplitude value ad (Xd, Yd) respectively, of a modulator resolution element (Xd, Yd) being substantially equal to −φc (Xm, Ym) and ac−1 (Xm, Ym).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.