Tearing and conformal transformation human interactive proof
US8359394B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2009 |
| Grant date | Jan 22, 2013 |
| Priority date | — |
| Expiry date | Aug 27, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/2133
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The HIP creation technique described herein pertains to a technique for creating a human interactive proof (HIP) by applying tearing and/or a conformal transformation to a string of characters while maintaining readability of text. In one embodiment, the technique tears a character string into two or more pieces and applies conformal transformation to warp the pieces in order to create a HIP. The transformation changes the shape and orientation of the characters but preserves angles of the characters which makes it easy for humans to recognize the characters after the transformation. Other embodiments of the technique create HIPs by applying tearing only to a string of characters, or by applying conformal transformation only to the character string.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.