Azure Documentation

Securing Azure Storage Tables

This document outlines the various security mechanisms and best practices for protecting your data stored in Azure Storage Tables.

Authentication and Authorization

Azure Storage Tables supports several methods for authenticating requests and authorizing access to your data. Choosing the right method depends on your application's needs and the level of security required.

Shared Key Access

Shared key access is the simplest way to authenticate with Azure Storage. You generate account access keys for your storage account, and these keys can be used to authorize any request to the storage service.

Shared Access Signatures (SAS)

Shared Access Signatures (SAS) provide a delegated way to grant access to resources in your storage account without giving away your account keys. A SAS token is a string that contains a security token that is signed by the account key. It can grant limited permissions (e.g., read, write, delete) for a specific period of time and to specific resources.

• User Delegation SAS: Signed with Azure AD credentials. Recommended for client applications.
• Service SAS: Signed with the account access key. Used for delegated access to storage account resources.

Azure Active Directory (Azure AD) Integration

For more robust security and centralized management, Azure Storage Tables integrates with Azure Active Directory. You can assign Azure AD roles to users, groups, or service principals to grant them permissions to access storage accounts and their resources.

Common Azure AD roles for storage include:

• Storage Blob Data Reader
• Storage Blob Data Contributor
• Storage Queue Data Contributor
• Storage Table Data Reader
• Storage Table Data Contributor

Using Azure AD authentication is the recommended approach for production applications as it aligns with modern identity and access management best practices.

Network Security

Securing your storage account at the network level is crucial to prevent unauthorized access from specific IP addresses or virtual networks.

Firewall and Virtual Network Rules

You can configure your storage account's firewall to restrict access to trusted IP addresses or ranges. You can also integrate your storage account with Azure Virtual Networks (VNet) by allowing access only from specific subnets.

Private Endpoints

Azure Private Endpoints allow you to access your Azure Storage account over a private endpoint in your virtual network. This ensures that traffic between your virtual network and the storage account stays within the Microsoft Azure network, enhancing security.

Data Encryption

Encryption at Rest

All data stored in Azure Storage Tables is automatically encrypted at rest using AES-256 encryption. This encryption is managed by Microsoft and requires no configuration on your part. You can optionally use customer-managed keys stored in Azure Key Vault for greater control over your encryption keys.

Encryption in Transit

Azure Storage supports HTTPS for all operations. It is highly recommended to always use HTTPS to encrypt data in transit between your client and the storage service, preventing man-in-the-middle attacks.

Auditing and Monitoring

Regularly auditing and monitoring access to your storage account is essential for detecting and responding to potential security threats.

Azure Monitor and Azure Activity Logs

Azure Monitor provides metrics and logs that can help you track storage account usage and identify suspicious activities. Azure Activity Logs record subscription-level events that occur in your Azure subscription, including operations performed on your storage accounts.

Azure Security Center

Azure Security Center offers advanced threat detection and recommendations for securing your Azure resources, including Azure Storage.

Best Practices Summary

• Prefer Azure AD authentication over shared key access.
• Use Shared Access Signatures (SAS) for delegated, time-limited access.
• Configure firewalls and virtual network rules to restrict network access.
• Always use HTTPS for data transfer.
• Enable auditing and monitoring to detect suspicious activity.
• Use Azure Key Vault for managing encryption keys if required.