Certificate-based digital signatures are the type of electronic signature that provides the highest level of assurance of a signer’s identity and complies with strict regulations. In this article, we will be learning to programmatically verify the digitally signed documents using Java. In one of the earlier posts, we have discussed the verification of digital signatures in documents using C#.
Java API for Signature Verification
This article uses Document Signature API for Java by GroupDocs. The GroupDocs.Signatures for Java supports the following types of electronic signatures:
- Barcode Signatures
- Form-Field Signatures
- Image Signatures
- Metadata Signatures
- QR-Code Signatures
- Stamp Signatures
- Text Signatures
So, it is better to prepare your workspace beforehand either by downloading the library from the downloads section or by setting the mentioned configuration in your Maven-based applications.
Steps to Verify Digitally Signed PDF Document using Java
By following the steps, you can verify the digitally signed documents. In this example, I have used a PDF document for verification, however, the same steps will work for MS Word documents, Excel spreadsheets, and Powerpoint presentations.
- Instantiate the Signature object with the source document.
- Instantiate the DigitalVerifyOptions class object and specify verification options.
- Call verify method of Signature and pass the specified verification options.
Below is the full sample source code that shows the above process. Here the Java code verifies the digitally signed PDF document. You may also perform verification of digitally signed word processing documents like MS Word DOC/DOCX, Excel spreadsheets XLS/XLSX, and presentations PPT/PPTX.
Today, we learned to verify the digitally signed MS Word, Excel, PowerPoint, and PDF documents using Java. You can explore more about GroupDocs.Signature for Java features using the documentation articles.