.xsig

Extension: XAdES XML Signature File

Developer: W3C and ETSI

The .xsig file extension signifies an XAdES (XML Advanced Electronic Signatures) XML Signature File. These files are crucial for ensuring the authenticity and integrity of digital documents. Developed collaboratively by the World Wide Web Consortium (W3C) and the European Telecommunications Standards Institute (ETSI), XAdES provides a robust and internationally recognized standard for digital signatures. Unlike simpler signature methods, XSIG files embed not only the digital signature itself but also extensive metadata. This metadata includes details like the signer’s digital certificate (verifying their identity), the precise timestamp of signature creation, and potentially other relevant information depending on the signing process. This rich metadata makes XSIG signatures more reliable and verifiable than many other signature formats.

Because XSIG files are essentially XML documents, you can technically open them with any text editor, though this will only display the raw XML code, which is difficult to interpret for most users. To properly view and verify the signature, you need specialized software capable of parsing and interpreting XAdES signatures. These programs often integrate with other document viewers or rely on cryptographic libraries to decode and validate the signature’s authenticity. Many digital signature software packages, including those used for document signing and verification, will support opening and validating .xsig files. You’ll need to consult the documentation of your specific digital signature software or search for a dedicated XAdES viewer to effectively utilize and understand the information contained within an .xsig file.