eIDAS (for “electronic IDentification, Authentication and trust Services”) is an European Union regulation.
Electronic Signature Formats compatible with eIDAS
eIDAS compelled the creation of electronic signature formats in order to comply with eIDAS regulation:
- XAdES
- CAdES
- PAdES
There is no signature format compatible with PKCS #7, as it was considered outdated when compared to CMS and it did not include some necessary compatibilities.
XAdES
XML Advanced Electronic Signatures (XAdES) is a set of extensions to XML-DSig recommentation in order to be compliant with eIDAS.
There are different subtypes of XAdES:
- XAdES-BES
- XAdES-EPES
- XAdES-T
- XAdES-C
XAdES is used to sign small files (up to 4 MB).
“FirmaXadesNet” is a .NET library in C# to generate XAdES signatures. You can find it on this external link.
There are at least the following Java implementations of XAdES:
- Java XML Digital Signature API
- Apache Santuario
- XAdES4j
- eID Digital Signature Service
CAdES
CMS Advanced Electronic Signatures (CAdES) is a set of extensions to Cryptographic Messagin System (CMS) that are compliant with eIDAS.
CAdES is used to sign big files (more than 4 MB).
PAdES
PDF Advanced Electronic Signatures (PAdES) that are compliant with eIDAS.
PAdES is used to check the information of both signature and content within PDFs.