Abstract: A method for embedding an optical security feature in a digital document with a virtual printer and a security feature service and then sending the digital document to a hardware printer.
Type:
Grant
Filed:
March 27, 2009
Date of Patent:
January 5, 2016
Assignee:
CRIMSONLOGIC PTE LTD
Inventors:
Weng Sing Tang, Fu Wang Thio, Chee Keong Chea, Jym Yew Meng Cheong
Abstract: The present invention relates to a method and system of embedding data in text documents. The method includes obtaining a document having dimensions and at least a first character and a second character and determining a length between the first character and the second character to define an inter-character space. A reference length is determined, where the reference length is a function of the dimensions of the text document. A threshold length is determined, where the threshold length is a minimum length wherein information is not encoded in the inter-character space if the inter-character space is not within the threshold length. The information is encoded into an altered inter-character space wherein a length of the altered inter-character space is an integral multiple of the reference length or a non-integral multiple of the reference length.
Abstract: The present invention relates to a method and system of embedding data in text documents. The method includes obtaining a document having dimensions and at least a first character and a second character and determining a length between the first character and the second character to define an inter-character space. A reference length is determined, where the reference length is a function of the dimensions of the text document. A threshold length is determined, where the threshold length is a minimum length wherein information is not encoded in the inter-character space if the inter-character space is not within the threshold length. The information is encoded into an altered inter-character space wherein a length of the altered inter-character space is an integral multiple of the reference length or a non-integral multiple of the reference length.
Abstract: A method and system for embedding data covertly in a text document using character rotation encoding. A character that occurs in first and second occurrences is selected, where the first occurrence of the character is a reference character and the second occurrence of the character as a rotatable character. The rotational orientation of the rotatable character is altered to produce an altered character with a predetermined rotation with respect to the reference character, wherein the rotation represents the embedded covert data. A text document is formatted based on the altered character.