It’s come to light that consistent email footers, even in encrypted .eml files, can pose a potential security risk. If attackers analyze similar patterns in footers across multiple emails, they could use this data as a tool to aid in decoding encrypted communications. Especially inside corporations where the email footers are almost identical for each individual person.
Why It Matters:
Even with encryption tools like Virtru protecting your sensitive data, consistent footers provide a predictable element that attackers might exploit. In cybersecurity, even minor consistencies in data can be leveraged to crack systems.
Recommended Actions:
To address this potential risk, organizations should consider the following measures:
- Randomized Email Footers
- Require employees to use customizable footers with varying content, spacing, or formatting.
- Introduce slight randomization, such as alternating phrasing or including non-critical, varied elements.
- Footer-Free Encrypted Emails
- Avoid adding footers to encrypted emails containing sensitive information.
- Develop a policy that excludes standard footer blocks in such scenarios.
- Enhanced Email Formatting Practices
- Incorporate random spaces, invisible formatting changes, or slight variations in email structure to make decryption more difficult.
- Strengthen Backend Security
- Implement backend scripting to remove or randomize footers automatically in emails flagged as sensitive.
- Use automated tools to detect patterns in outgoing email content and introduce variability.
- Educate Employees
- Train staff to understand how even small consistencies can create vulnerabilities.
- Encourage the use of encryption tools alongside these additional protective practices.
Moving Forward:
As email-based attacks become increasingly sophisticated, adapting our protocols is essential. By eliminating predictable patterns like consistent footers and introducing backend solutions, we can significantly reduce the risk of email decryption.
Protecting sensitive communication requires a layered approach. While tools like Virtru provide robust encryption, it’s critical to address overlooked vulnerabilities like repetitive footers to stay ahead of potential threats. Let’s take proactive steps to safeguard our data.
