How to Use Cryptography to Secure Endpoint Data at Rest and In Transit

November 27, 20235 min read

Cryptography plays a critical role in securing data both when it is stored (at rest) and when it is being transmitted (in transit). By utilizing various cryptographic techniques and tools, organizations can protect sensitive information from unauthorized access and breaches.

Securing Endpoint Data at Rest

Data at rest refers to all data in storage while not being actively accessed or processed. Protecting data at rest is important to prevent unauthorized users from accessing sensitive information if they gain physical or logical access to the storage.


  • Full Disk Encryption (FDE): This is one of the most effective ways to protect data at rest. FDE encrypts all the data on the disk drive and requires authentication during the system boot process.
    • To implement FDE, you can use tools like BitLocker for Windows or FileVault for macOS.
    • Ensure that the encryption keys are securely stored and managed.
  • Volume and Virtual Disk Encryption: Instead of encrypting the entire disk, you can encrypt specific volumes or create encrypted virtual disks.
    • Consider tools like VeraCrypt for creating encrypted containers.
  • File-Level Encryption: This is useful for encrypting individual files or folders.
    • Use EFS (Encrypting File System) in Windows to encrypt files or AxCrypt for a platform-independent solution.

Key Management

  • Encryption Key Generation: Use strong, cryptographically secure algorithms to generate keys.
  • Key Storage: Store encryption keys separate from the encrypted data, ideally in a hardware security module (HSM) or using key management services provided by cloud providers.
  • Key Rotation: Regularly change encryption keys to reduce the risk of compromise.
  • Access Controls: Implement strict access controls to ensure only authorized users can retrieve encryption keys.

Best Practices

  • Regularly Update Security Patches: Keep the operating system and all security tools up to date to protect against vulnerabilities.
  • Least Privilege Access Model: Limit system access to the minimum necessary for users to perform their job functions.
  • Data Backup: Regularly back up encrypted data and ensure backups are also encrypted and stored securely.

Securing Endpoint Data in Transit

Data in transit refers to data actively moving from one location to another, such as across the internet or through a private network.

Encryption Protocols

  • TLS/SSL: Use Transport Layer Security (TLS) or Secure Sockets Layer (SSL) to encrypt data during transmission over the internet.
    • Ensure that servers are configured with the latest version of TLS and with strong cipher suites.
  • VPN: Use a Virtual Private Network (VPN) for secure remote access to corporate resources.
    • Configure the VPN with strong encryption protocols, such as IKEv2 or OpenVPN.

Email Security

  • S/MIME or PGP: Use Secure/Multipurpose Internet Mail Extensions (S/MIME) or Pretty Good Privacy (PGP) to encrypt email communications.
    • Educate users on how to use these tools and ensure they understand the importance of secure email exchanges.
  • Secure File Transfer: Use secure file transfer protocols like SFTP or FTPS when transferring sensitive files.

Mobile Data Security

  • Wi-Fi Security: Ensure that Wi-Fi networks use WPA2 or WPA3 encryption.
  • Mobile Device Management (MDM): Implement an MDM solution to manage and secure mobile devices, including encrypting data in transit.

Network Security

  • Firewalls: Deploy firewalls to monitor and control incoming and outgoing network traffic based on predetermined security rules.
  • Intrusion Detection and Prevention Systems (IDPS): Use IDPS to identify and respond to suspicious network activities.

Best Practices

  • Security Audits and Monitoring: Conduct regular security audits and monitor network traffic to identify and respond to threats.
  • User Training: Educate employees about the importance of data security and best practices to avoid data exposure.
  • Zero Trust Network Access (ZTNA): Implement a Zero Trust framework where trust is never assumed and is continually verified.

By carefully applying these cryptographic methods and best practices, organizations can significantly enhance the security of endpoint data both at rest and in transit. Regular security assessments and adapting to new threats are essential for maintaining robust data protection in an ever-evolving security landscape.