Secure Archive

• 03/12/2025
• 16 minutes to read

With the Secure Archive, all digital documents that your organization uses for bookkeeping purposes and which are processed using Continia Document Capture and/or Continia Expense Management can be secured and preserved in their original form – so that no one accidentally deletes them or modifies them in any other undesirable way. In full compliance with local and national legislation, all of your archived documents are fully traceable throughout the archive period that you define. The built-in logging functionality automatically records every step in the processing of the documents, from initial receipt to final posting.

If you're only interested in the logging functionality, you can enable this as a standalone feature. By doing so, you have the processing of all Microsoft Dynamics 365 Business Central documents tracked and logged automatically – not just the documents processed by Continia's solutions –, without any of the minor restrictions that come with the Secure Archive.

For information on how to set up the Secure Archive and/or the logging functionality, see Setting up the Secure Archive.

With the Secure Archive, Document Capture and Expense Management have achieved certification in the DACH region (i.e.: Austria, Germany, and Switzerland) as audit-compliant document management systems ('AC-DMS ready'). Known in Germany as 'PK-DML ready', this certification has served as the standard for legally compliant and audit-proof management of electronic documents for more than two decades. For the actual certificate awarded to Continia, see VOI Compliance Certificate.

The scope of the archive

The Secure Archive stores purchase documents that have been processed by Document Capture and/or Expense Management and which are eventually posted and used for bookkeeping. This includes, but is not limited to, supplier invoices, supplier credit memos, scanned purchase documents, downloaded electronic documents, employee expense attachments received by email, and documents dragged into Document Capture or Expense Management.

Due to company policies, storage space limitations, or for any other potential reasons, your organization may have chosen to host your document archive outside the database (for example, using local file storage or Azure Blob Storage). In these cases, storage security is the sole responsibility of your organization.

Key features

One of the main features of the Secure Archive is that it blocks users from deleting any of the documents that are stored in the archive. This means that the standard Business Central purchase setting Allow Document Deletion Before <DATE> can't be used within the archive period that you've defined.

Another main feature is that the Secure Archive ensures the originality of each document that's stored in the archive. It does so through the use of hash functions, which you can read more about below under The use of hash functions.

For Document Capture, if you realize that something isn't quite right with one of your documents (for example, the quality of the scanning is poor), mark it as deleted. This doesn't delete the document entirely, the document is kept in the Secure Archive behind the scenes – and it's fully accessible from there.

You can also add a document after posting, such as a better scan. However, the new document is marked Added after posting to indicate that it's not the original document.

The Secure Archive provides full backward traceability. From any given entry in General Ledger Entries and Vendor Ledger Entries, you can use Find entries to trace the original document as you received or scanned it, including all metadata such as sender email and time stamps. This traceability is retained even when you split or merge documents.

When the Secure Archive is enabled, any image file that's imported with Expense Management is converted into a PDF that's digitally signed. The original file is also kept in the archive. File signing takes place in the following situations:

• When you upload the file using the Expense Portal or the Expense App (mobile app), as long as Sign Documents has been enabled and synchronized with Continia Online.
• When the file is uploaded from within Business Central and Sign Documents has been enabled in the setup.

The use of hash functions

To optimize security and ensure document originality, hash functions are used for both Document Capture and Expense Management, but in slightly different ways. The hash functionality of each of the solutions is described in the following two sections.

Hash functions for Document Capture

Every document imported using Document Capture, either through the PURCHASE category or by being dragged into Document Capture, automatically gets a hash associated with it (SHA1). This hash is recalculated if the imported document is split or merged, if pages in the document are rotated, or in case the order of any document pages is changed. The recalculated hash value replaces the original hash value and forms a new basis for comparison.

When you post a document, the hash values of all attached documents are calculated again and checked against the original hash values. If they don't match, the posting is rejected. In such cases, the only way forward is to delete all documents and start over again. This deletion is recorded in the log, together with all other document activity.

When you view a posted document, the hash values are calculated and checked against the original hash values again. If they don't match, this is indicated on the General FastTab, under Document Log, where the following text is displayed in red: "One or more documents have been changed after posting!". To open the Document Log Summary, which shows which documents have been altered, click this text.

If the original and the newly calculated hash values do match, Document Log displays a message with the number of document log entries – for example, 2 Document Log Entries – instead of the red warning message mentioned above. If you click this message to open the Document Log Summary, the File Hash Check column reads OK to indicate that there's a perfect match between the original and the current hash values, meaning that the documents are unchanged and haven't been tampered with in any way.

Hash functions for Expense Management

As with Document Capture, every document imported using Expense Management, either when added manually in Business Central or downloaded via synchronization with Continia Online, has a hash associated with it (SHA1). The Secure Archive uses such hash values as a basis for comparison to ensure that incoming documents remain unchanged throughout the process until posting.

When you post a document, the hash values of all attached documents are calculated again and checked against the original hash values. If they don't match, the posting is rejected – and an error message is displayed along with an error comment in the Comments section. In such cases, the only way forward is to delete all documents and start over again. This deletion is recorded in the log, together with all other document activity.

The log functionality

For both Document Capture and Expense Management, the overall log functionality covers two different logging systems:

• The system log
• The document log

The system log automatically logs every change made to the Secure Archive setup. When a user configures any of the following setup settings, the changes are immediately logged in the system log:

• Enable Secure Archive
• Document Activity Logging
• Archive Period Type
• Minimum Archive Period
• Sign Documents (only applicable to Expense Management)

The document log automatically logs the activity of all documents processed by Document Capture and/or Expense Management, from the moment they enter the system until they're posted.

There are differences between Document Capture and Expense Management in terms of what's logged in the document log. The following two sections provide an overview of the logged activity for Document Capture and Expense Management respectively:

Logged activity for Document Capture documents

Logged activity for Expense Management documents