FormatShiftHow to Open a .P7S File & Extract Embedded Document from Signature
Reading time: 4 min•Digital Signature Guide
Need to extract document from .P7S or .SIG right now?
Our free tool automatically detects embedded documents and extracts them with 1 click.
What is a .P7S File?
A .p7s file is a cryptographic container based on the PKCS #7 standard. It is widely used to verify digital signatures and identity of signers.
What is the Difference Between .SIG and .P7S?
Both formats encapsulate X.509 certificates and signature data, but differ in payload placement:
- Detached signature: Contains only the signature digest. Requires original companion document.
- Attached / Enveloped signature: The original document is embedded INSIDE the signature file itself. Standard PDF viewers cannot open it.
How to Extract Document from Signature without CryptoPro
Double clicking a .p7s file usually throws an error. Installing heavy software like CryptoPro is not necessary.
To extract the document instantly on FormatShift:
- Navigate to our signature verifier /verify-sig.
- Drag & drop your .p7s or .sig file into the upload zone.
- The tool inspects the certificate and reveals an instant green download button with the extracted document.
Frequently Asked Questions about .P7S
Is it safe to verify signatures online?
Yes. On FormatShift, decoding and extraction happen 100% locally in your browser RAM without uploading files to any server.
What if the certificate has expired?
An expired certificate cannot be reused for new signatures, but past signatures created during its validity remain valid.