The standard
ASiC stands for Associated Signature Containers. The specification, ETSI EN 319 162-1, describes how to bind one or more files to signatures or time stamps inside a single archive. It defines two forms:
- ASiC-S (Simple): exactly one data file with its signature or time stamp.
- ASiC-E (Extended): any number of data files and any number of signatures.
ASiC is among the formats that public bodies in the EU must accept under the eIDAS implementing rules.
Physical layout
| Entry | Required | Content |
|---|---|---|
mimetype | Recommended, first and uncompressed | application/vnd.etsi.asic-e+zip |
| Data files | Yes | The signed documents, in the root or in folders |
META-INF/manifest.xml | With XAdES | OpenDocument-style list of files and media types |
META-INF/signatures*.xml | With XAdES | One XAdESSignatures document per signature |
META-INF/ASiCManifest*.xml | With CAdES | References and digests of data files |
META-INF/signature*.p7s | With CAdES | Binary signature over the ASiC manifest |
How a signature is bound to files
With XAdES, every signature holds a ds:Reference for each data file: the file's URI in the archive and its digest, typically SHA-256. The signer's private key signs the block containing those digests. Change one byte of any file and its digest no longer matches.
With CAdES the indirection is explicit: an ASiCManifest lists the digests, and the binary signature covers that manifest.
Baseline levels
| Level | Adds |
|---|---|
| B-B | Signature, signing certificate, signed properties |
| B-T | Time stamp over the signature |
| B-LT | Certificates and revocation data for long-term validation |
| B-LTA | Archive time stamps for long-term preservation |
Related formats
BDOC 2.1 is an Estonian profile of ASiC-E with XAdES; EDOC is the Latvian equivalent. They share the layout, which is why one viewer opens all of them. DDOC is the exception: an older single XML file rather than a ZIP.
Seeing it in practice
Drop a container onto ASiCE Viewer and open Technical files to browse mimetype, the manifest and each signature as formatted XML. To follow the same steps with command-line tools, read ASiC-E file reader.
Frequently asked questions
Is ASiC-E an open format?
Yes. It is a published ETSI standard built on ZIP and W3C XML Signature, and anyone may implement it.
What is the MIME type of an ASiC-E file?
application/vnd.etsi.asic-e+zip. The simple form uses application/vnd.etsi.asic-s+zip.