Overview of Supported Signature Formats

Overview of Supported Signature Formats

Signature formats define how digital signatures are technically stored and represented. They ensure that electronic signatures can be securely, verifiably, and legally embedded in digital documents. Depending on the area of application, different standards are used.
The following article provides an overview of the signature formats supported by the respective signature solutions.


SIGN8 Web App
Digital signatures and seals created via the web application use the PAdES format.

SIGN8 USB-Token
The USB tokens serve as a "storage medium" for the qualified certificate. To create a signature, software with signing functionality (e.g., Adobe) is required. The following overview shows which signature formats are supported by common PDF programs with signing capabilities:

Software
PAdESXAdESCAdESPKCS#7PKCS#11
AdobeX


X
SecSignerXXXXX
Kofax Power PDF Advanced

XX

Info

Please note that there are different types of certificates, such as the qualified certificate for the Qualified Electronic Signature (QES) and the authentication certificate for identity verification on specific portals.

The authentication certificate can be purchased as an add-on to the USB token.

​
SIGN8 CSC API
The SIGN8 CSC API covers a wide range of use cases – from traditional document signatures to web-based transactions.

A key feature of the SIGN8 CSC API is its support for the four common signature formats:

  • CAdES – for signing binary data (e.g., ZIP, Office files)

  • PAdES – for signatures within PDF documents

  • JAdES – for modern, JSON-based applications and web services

  • Raw PKCS#1 – for simple, direct signatures without additional structure or metadata – typically used in cryptographic contexts or for embedding in other formats

It accepts both arbitrary hash values and Base64-encoded documents as input.


SIGN8 Workflow API
Digital signatures and seals created via the Workflow API use the PAdES format.


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