Extract text from digital signature files (SIG)
To convert SIG signatures to another format, you need CryptoPro CSP or other Encoded software.
To convert other file formats to the "Detached Signature File" file type, you need software like CryptoPro CSP or a similar tool.
A .SIG file is primarily a cryptographic digital signature used to confirm the authenticity, origin, and integrity of another file. While it occasionally acts as an attached signature container enclosing a full document, it is most frequently encountered as a detached signature. These files are generated and managed by specialized cryptographic software, heavily featuring CryptoPro CSP (often utilizing Russian GOST standards), as well as GnuPG (GPG) and PGP systems. Minor historical uses also include Broderbund The Print Shop documents or Epic Games Unreal Engine package signatures.
The main disadvantage of a .SIG file is its reliance on strict environmental prerequisites. As a detached signature, the file is entirely useless on its own; it requires the exact original file to execute a verification check. Furthermore, the format is usually a binary blob or a Base64 encoded block (such as PKCS#7 / CMS) that cannot be read natively by operating systems or web browsers. Users who lack the correct cryptographic software, the matching public keys, or the required proprietary vendor licenses face immediate roadblocks when attempting to verify or extract the signed data.
To overcome these hurdles, conversion or extraction is often required. If the .SIG file is an enveloping (attached) signature, extract the enclosed payload directly to a PDF, ZIP, or original binary format. For inspection and debugging, convert the binary .SIG to a TXT file to view the raw Base64 (PEM) encoding. If you are managing certificates, extracting the signer's certificate to PEM or DER ensures broader compatibility across different systems. Drag and drop your file to analyze and convert it - free, online, and without installing software.
Convert.Guru analyzes your SIG file, detects the exact format, and lets you read the text inside.
Users also converted PGP, PDF, CDW, ZIP, XML, PLAN, JPG, SGN, SIGN, P7S, WEBARCHIVE, SIC and XSB files.
If you want to convert SIG file to PDF, JPG, PNG, GIF, BMP, TIFF, TIF, WEBP, ICO, CUR, PSD or PSB, you can use CryptoPro CSP or similar software from the "Cryptographic Digital Signature" category. In the File menu, look for Save As… or Export….
To convert RAW, PNG, AI, NEF, PSB, DNG, SVG, GIF, EPS, JPG, ARW or PDF files to SIG, try CryptoPro CSP or another comparable tool in the "Cryptographic Digital Signature" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our SIG converter.