How to Encrypt Sensitive Data in Transit and at Rest

November 26, 20235 min read

Encryption is a critical security measure for protecting sensitive data, whether it is being transmitted over a network (in transit) or stored on a device (at rest). By encrypting data, we ensure that even if it is intercepted or accessed without authorization, it remains unreadable and secure.

In Transit

Data in transit refers to any data that is being transferred between systems, whether it is over the internet, across a private network, or through a local connection between devices. This section will delve into how to encrypt data as it moves from one location to another.

Use Secure Protocols

  • HTTPS (SSL/TLS): Use Hypertext Transfer Protocol Secure (HTTPS) for web-based data transmission. This protocol uses SSL/TLS encryption to secure data between the web server and browser.
  • FTPS/SFTP: For file transfers, use FTP Secure (FTPS) or Secure File Transfer Protocol (SFTP), which add a layer of encryption to the traditional FTP communications.
  • Secure Email Protocols: Utilize protocols like Secure/Multipurpose Internet Mail Extensions (S/MIME) for email encryption.
  • Virtual Private Networks (VPNs): Implement VPNs to create a secure tunnel for data traffic over public networks.
  • Wireless Encryption: Use Wi-Fi Protected Access II (WPA2) or the newer WPA3 for encrypting data on wireless networks.

Implement TLS Best Practices

  • Strong ciphers: Choose strong encryption ciphers and algorithms when configuring TLS.
  • Updated software: Keep your TLS/SSL libraries up to date to protect against known vulnerabilities.
  • Certificate management: Use certificates from a trusted Certificate Authority and manage them properly, ensuring they do not expire.

At Rest

Data at rest is any information stored on a device, including databases, files, or backups. Proper encryption of this data prevents it from being accessible to unauthorized people who might gain physical access to the storage.

Full Disk Encryption (FDE)

  • Native Encryption Solutions: Utilize operating system-native solutions, like BitLocker for Windows or FileVault for macOS, to encrypt the entire disk.
  • Third-party Software: Consider using reputable third-party tools that provide full disk encryption for various operating systems.

Database Encryption

  • Transparent Data Encryption (TDE): Use this method in SQL Server and Oracle databases to encrypt the database files directly.
  • Application-Level Encryption: Encrypt sensitive fields before storing them in the database using application code or libraries.
  • Encrypted Backups: Ensure that database backups are also encrypted.

Encrypting Individual Files and Folders

  • Encryption Tools: Use tools like GnuPG for file-level encryption, which provides options for encrypting individual files and folders.
  • Enterprise Encryption Solutions: Large organizations should consider enterprise-level encryption platforms that manage keys and policies centrally for file and folder encryption.

Key Management

  • Secure Storage: Keep encryption keys in a secure key store or a hardware security module (HSM).
  • Key Rotation: Regularly change encryption keys and implement processes to handle key lifecycle including creation, distribution, rotation, and destruction.
  • Access Control: Only authorized users or systems should have access to encryption keys.

General Best Practices

Regardless of the state of the data, some best practices should be followed:

  • Audit and Compliance: Regularly audit your encryption practices and ensure they comply with relevant regulations and industry standards.
  • Minimal Access: Implement the principle of least privilege, so only necessary individuals or systems have access to sensitive data.
  • Regular Updates: Stay on top of security patches and updates for your encryption software and protocols.
  • Use Strong Passphrases: For keys that require a passphrase, ensure they are strong and resistant to brute force attacks.
  • Training and Awareness: Provide training to all employees handling sensitive data about the importance of encryption and secure data handling practices.
  • Disaster Recovery Plan: Ensure that your disaster recovery plan includes provisions for backing up and recovering encrypted data.

By following these guidelines for encrypting data both in transit and at rest, you can significantly enhance the security of your sensitive information and reduce the risk of data breaches or unauthorized access.