One aspect of the present invention discloses a client device for content security. The device includes: an application execution unit configured to control content in response to a content control command requested in a user level; a DRM agent configured to communicate with a DRM server and the application execution unit in the user level, to detect the content control command, to receive an encryption/decryption key and security policy for content from the DRM server, to provide the received encryption/decryption key and security policy to a client kernel module, and to transmit an encryption/decryption request; and the client kernel module configured to receive the encryption/decryption key and the security policy, to store the encryption/decryption key and security policy in a secure box of a kernel level, and to perform encryption or decryption on the content based on the encryption/decryption key and security policy in response to the encryption/decryption request.

A computer-implemented process can be operated to create a watermarked copy of a unique original copy of an electronic sales receipt in a first computerized device to a second computerized device. The watermarked copy includes an electronic watermark identifying the copy. The process includes creating the watermarked copy of the electronic sales receipt by copying information from the original copy of the electronic sales receipt to the watermarked copy and providing the electronic watermark within the watermarked copy.

The invention relates to a security element applied onto printing substrates (bank notes, securities, product packagings, identity cards/labels or other similar documents) by printing, comprising a unique identifier as primary information visible to the naked eye and secondary information protecting against copying non-visible to the naked eye. The unique identifier is typically a point code. Said secondary information is represented by a structure with the largest dimension of 2 to 40 microns, and due to printing distortions arising when the security element is applied onto a printing substrate, said secondary information is non-reconstructable from the print of the security element and a statistically analyzable inherent feature is associated to it. The invention also relates to a printed matter with such an inventive security element and to a method to check authenticity of a printed matter with the inventive security element in visible light (380-750 nm).

Some implementations may provide a computer-implemented method for validating a digital document, the method including: receiving, at a computing device, the digital document comprising at least two digital watermarks, the digital document issued by a central entity; retrieving a first digital watermark from the digital document, the first digital watermark visually presented at a first time point; retrieving a second digital watermark from the digital document, the second digital watermark visually presented at a second time point, the second digital watermark being different from the first digital watermark and the second time point being different from the first time point; and reading the digital document based on the retrieved first and second digital watermarks.

The system is disclosed for visual marking sensitive documents for leak prevention. Each time an action is taken with regard to a document (e.g., creation, viewing, downloading), that action is added to a distributed ledger, essentially creating a unique hash for a new instance of the document. This new hash is visually embedded in the document as a code comprising a plurality of differently shaded pixels, wherein some of the pixels directly encode information regarding the document (e.g., an account that generated the new instance of the document, a date, a time, a unique ID for the document, etc.) and some of the pixels do not encode information. The code is capable of being scanned either digitally or physically on a printed version of the document, such that the immediate source of the document, corresponding to who leaked the document, is able to be discerned.

Methods and systems for rendering a watermark, can involve creating a digital watermark by applying grayscale inversion and contrast reduction to a document, resulting in a visually distinguishable pattern and rendering a digital watermark on the document in a manner that allows verification at different viewing angles. The digital watermark can be created using a digital swatch sheet of multiple gray values. The document can be viewed varying angles to verify the validity of the document based on the visibility and characteristics of the digital watermark. The digital watermark may be modified on predetermined parameters to facilitate enhanced security against fraud.

The system is disclosed for visual marking sensitive documents for leak prevention. Each time an action is taken with regard to a document (e.g., creation, viewing, downloading), that action is added to a distributed ledger, essentially creating a unique hash for a new instance of the document. This new hash is visually embedded in the document as a code comprising a plurality of differently shaded pixels, wherein some of the pixels directly encode information regarding the document (e.g., an account that generated the new instance of the document, a date, a time, a unique ID for the document, etc.) and some of the pixels do not encode information. The code is capable of being scanned either digitally or physically on a printed version of the document, such that the immediate source of the document, corresponding to who leaked the document, is able to be discerned.

Systems and methods for watermarking objects of a digital dataset are disclosed. The method includes, at a first moment in time, acquiring a watermark message of a first size and generating a plurality of sub-messages based on the watermark message. The plurality of sub-messages are indicative of encoded portions of the watermark message. Each of the plurality of sub-messages is different from the watermark message and having a second size, the second size being smaller than the first size. The method also includes generating a watermarked object by embedding a given object from the digital dataset with a given one of the plurality of sub-messages, in lieu of the watermark message.

According to examples, an apparatus may include a processor and a memory on which are stored machine-readable instructions that when executed by the processor, may cause the processor to extract text from a document. The processor may retrieve images associated with characters in the extracted text and generate a stitched image using the retrieved images. The processor may watermark the stitched image and replace the characters in the document with the images associated with the characters from the watermarked and stitched image.