Document Edge Encoding for Stack Integrity Verification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods lack a reliable way to verify the authenticity and integrity of a stack of documents, such as voter ballots or test papers, as individual documents can be secured but not the stack as a whole.

Innovation Solution

A method and system that involves generating a verification image, segmenting it into slices, and printing these slices on the edges of document sheets, which collectively form a verification image when stacked, allowing for the integrity of the document stack to be verified by comparing the expected and actual images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If individual documents are encrypted or watermarked, then document-level security is improved, but stack-level verification capability deteriorates

Engineering Contradiction:

Improvedocument securityVSAvoidstack integrity verification capability

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent combines individual document security measures with stack-level verification by integrating verification images into each document. The verification image is segmented into slices and embedded in each document, allowing both individual document authentication and stack integrity verification through the collective arrangement of slices forming a complete verification image.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The verification image is divided into multiple slices that are distributed across different documents in the stack. Each document contains a portion of the verification image, and the complete verification image is reconstructed when all documents are properly stacked, enabling verification of the entire stack's integrity.

Inventive Principle:

Principle #1Segmentation

2Reliability

If verification images are printed on documents, then stack integrity verification is improved, but document storage space deteriorates

Engineering Contradiction:

Improvestack integrity verificationVSAvoiddocument storage space

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

Instead of placing complete verification images on each document, the patent applies only segmented slices of the verification image to specific local areas (edges or corners) of documents. This localized approach provides the necessary verification capability while minimizing the use of document space.

Inventive Principle:

Principle #3Local quality

3Reliability

If verification slices are placed on document edges, then stack verification capability is improved, but ease of operation deteriorates

Engineering Contradiction:

Improvestack verification capabilityVSAvoiddocument handling

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The verification slices may incorporate color-coded elements or use distinct visual characteristics that make them easily identifiable. This helps operators quickly locate and verify the presence of verification slices on document edges without requiring detailed inspection, thereby improving ease of operation.

Inventive Principle:

Principle #32Color changes

Data Source

PatentUS20260017472A1Variable edge document encoding for secure document storage and retrieval

Publication Date: 2026.01.15 XEROX CORP

AI summary

This document discloses a method and system for assessing integrity of a stack of ballots or other documents. A processor receives a first set of electronic source document files, each of which includes content of a corresponding source document. The processor generates a verification image, segments the verification image into slices, and causes a print device to print verification document sheets. Each verification document sheet includes data from one of the source electronic document files and, on an edge of the sheet, a unique one of the slices of the verification image. The verification document sheets are stacked so that the slices appear on a side of the stack and, when all of the verification document sheets have been placed onto the stack, the slices collectively form the verification image.