System and method for secure font subset distribution
US6065008A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1997 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Oct 1, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99939
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
This invention concerns a system and method for securely distributing subsetted fonts from a distributor to a client. The system includes a signing module to construct an authentication tree having leaves formed of glyphs, one or more intermediate levels of nodes computed as one-way functions of the glyphs, and a root computed as a one-way function of the nodes. The signing module digitally signs the root of the authentication tree using a private signing key unique to the font creator or distributor. The system has a subsetting module to construct a font subset file that contains selected glyphs and other data to be included in a font subset. The font subset file also holds the digitally signed root of the font authentication tree and one or more authentication values of the authentication tree that represents non-selected glyphs and data of the font that are not contained in the font subset. The font subset file is distributed to requesting clients. An authentication module at the client authenticates the font subset file received from the distributor. The authentication module reconstructs the root of the authentication tree using the selected glyphs and data in the font subset …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.