International Business Machines Corporation

Florian Pestoni

Cynthia Dwork

Moni Naor

Mario Blaum

Jehoshua Bruck

Jorge L Sanz

Felix Gustavo Safar

A machine-readable check comprising a check and a machine-readable image block printed on the check. Preferably, the image block is a two-dimensional print code.

Machine-readable checks

A system and method are provided for producing verified signatures on documents such as checks and affidavits. Initially, a customer who is to obtain a verified signature, at some point in time, registers with a signatory authority, and a secret key, having public and private components, is established uniquely for that customer. When a document requires a verified signature, the customer presents the document and proof of his/her identity, such as a preprogrammed computer-interfacable card, to a signature system. Typically, such a system is to be available at an institution, such as an office, bank, or post office, where such services will routinely be used. The system accesses the archive of the private portion of the customer's key, and generates an encoded signature based, in part, on the content of the document. Accordingly, when a recipient of the document later wishes to verify the signature, the recipient uses the customer's public key to decode the signature. It is then straightforward to verify the signature against the content of the document.

System and method for verifying signatures on documents

A system and method are provided for facilitating proof that a specific item, such as a document, has been sent via a communication medium, such as the mail service of the United States Postal Service, at a specific time. A bit map image is produced, such as by scanning a hard copy document. Preferably the bit map is compressed into a data string and hashed. The hash file is signed by a certifying authority, such as the USPS, using an existentially unforgeable signature scheme. The original document, a code representation of the string, and a code representation of the signature are sent via the communication medium. As a result, the combination of materials sent provides proof of the authenticity of the content of the document.

System and method for certifying content of hard-copy documents

A method and apparatus for encoding and detecting data which can be represented in a physical array of modules recorded on a medium. Information is encoded in 'image-blocks'. An image-block comprises a plurality of 'sub-blocks'. Sub-blocks comprise a plurality of 'modules'. A module is the smallest unit of information within the image-block. Discrete contiguous portions of each sub-block of an image-block taken together are encoded into an outer codeword. A plurality of these outer codewords are generated and recorded across each sub-block. A portion of the information that is to be recorded within each sub-block is encoded in a plurality of inner error detection and correction codewords, each preferably stored entirely within one corresponding sub-block. Accordingly, small scattered random errors can be corrected locally by using information entirely contained within the sub-block. If a large area within a sub-block is corrupted, the information contained in each other sub-block may be used to reconstruct the data that was recorded in the corrupted sub-block. The inner codewords are 'interleaved' to provide a maximum distance between parts of the same codeword.

Growing community of inventors

Buenos Aires, Argentina

Florian Pestoni