What is the most secure way to share files?
Efficiency question :
File sharing is essential to business operations, whether among employees or with clients and external partners.
Sending documents as email attachments creates a risk: once a file has been sent, controlling its use and redistribution becomes difficult.
A more secure approach is to keep documents in a centralized environment, such as SharePoint or OneDrive, and send a link to access them.
This method supports collaboration while allowing control over recipients, permissions, and, in some cases, how long sharing remains active.
Key issues:
The main issue is enabling information sharing without compromising confidentiality.
Determine who may access documents, whether recipients can edit them or only view them, and how long access should remain available.
Sensitive information, including financial data, personal information, and confidential documents, requires additional precautions.
Sharing links should also not remain active unnecessarily after an engagement or collaboration ends.
Challenges:
The main challenge is providing a sharing method simple enough that employees do not resort to personal or unauthorized solutions.
Anonymous links, which anyone possessing the link can use, are especially risky when they provide access to confidential documents.
Another challenge is preventing uncontrolled file distribution. Even when downloading is blocked, an authorized user may still reproduce some information.
Protection mechanisms should therefore be matched to the sensitivity of the documents.
Technology:
Microsoft SharePoint and OneDrive allow documents to be shared through secure links.
Key features include:
- Sharing with specifically identified people.
- View-only or editing permissions.
- Sharing-link expiration, depending on available settings.
- Download blocking for certain sharing scenarios.
- Revoking access when it is no longer needed.
Microsoft Entra ID strengthens user authentication, including through multifactor authentication.
For sensitive documents, Microsoft Purview can apply sensitivity labels and, depending on licensing and configuration, encryption that continues to protect files even after they are downloaded.
Data loss prevention (DLP) policies can also restrict certain unauthorized sharing activities.
Developer's advice:
Prefer sharing SharePoint or OneDrive links rather than sending email attachments.
For confidential documents, use links restricted to specifically identified people and grant only the permissions required.
When sharing is temporary, set an expiration date or establish an access-removal procedure.
For particularly sensitive information, consider file-level protection with Microsoft Purview rather than relying solely on the permissions of the storage location.
Avoid multiplying sharing methods. Employees are more likely to follow a simple, consistent, secure procedure.
The goal is to make document exchange easier while retaining control over who can access the information.