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Secure File Sharing via Email: A Comprehensive Guide

by Robert Dougherty updated April 11, 2023 Secure File Sharing

Reading Time: 7 minutes

Email has become an invaluable tool for a variety of organizations and their employees to share files simply and quickly. It is especially important for organizations with remote workers, who often need to send and receive information to stay productive and keep projects on track. Oftentimes, the information shared, whether in an email body or file attachment, contains sensitive information. Without the ability to share files securely, organizations risk exposing this information to unauthorized users like malicious actors.

In order to mitigate the risk of a cyberattack or data breach that exposes sensitive content found in emails and file attachments, organizations can employ several key technologies and best practices. Protecting email and the file attachments they contain not only protects personally identifiable information and protected health information (PII/PHI), intellectual property, and other sensitive information but also lets organizations demonstrate compliance with data privacy regulations and standards.

In this post, we will discuss the importance of secure file sharing via email and the potential risks associated with it. We will also introduce the key concepts and techniques for ensuring secure file sharing via email and explore how they can be used to mitigate potential risks. Finally, we will provide best practices for organizations and individuals to ensure the security of the sensitive content they share in emails and file attachments.

Risks of Sharing Files via Email

File sharing with email has become a preferred method of exchanging files quickly and easily. However, organizations grossly overestimate their email server’s ability to share files securely. And as with most methods of content exchange, there are inherent risks associated with email file sharing that are often overlooked. Common security risks associated with email file sharing include:

Unencrypted Files

The biggest security risk associated with email file sharing is sending unencrypted files. When files are sent through email, they are typically sent in plaintext format, meaning that anyone with the ability to intercept the email traffic, like during a man-in-the-middle attack or phishing attack, will have access to the unencrypted information.

Viruses and Malware

Any email attachment can potentially contain malicious code, such as viruses, worms, and spyware. A malware attack occurs when a user opens an infected email attachment. The victim’s computer becomes infected and the malicious code spreads throughout the organization’s network.

Spoofing

Spoofing is another common security risk associated with email file sharing. Hackers can easily create messages that appear to originate from legitimate sources and use these messages to trick users into downloading malicious attachments.

Phishing

Phishing is a type of scam that involves sending emails that appear to be from legitimate sources in order to obtain sensitive information, such as usernames, passwords, and credit card numbers.

Misdelivery

Finally, email file sharing is also susceptible to misdelivery, leading to a data leak. This typically happens when an employee inadvertently sends an email to the wrong recipient. Even if the wrong recipient returns the email and file attachment, technically a data breach and compliance violation have still occurred.

Taking Precautions to Protect Sensitive Content Shared via Email

Due to the high risk of security breaches, it is of utmost importance that users take the proper precautions to protect their sensitive content. The first step is to ensure that all files that are shared via email are encrypted. Email encryption ensures that even if the files are intercepted, they cannot be read without the encryption key. In addition, end-to-end encryption ensures emails and file attachments remain encrypted through the entire email journey.

Users should ensure that any email file sharing is done through a secure email service. Secure email services provide enhanced security features, such as encryption, authentication, and access control measures.

Finally, users should always be aware of phishing emails and not open any email attachments from unknown sources. Phishing emails are a common security risk associated with email file sharing and users should take the necessary precautions to protect against them.

Best Practices for Secure File Sharing via Email

When it comes to securely sharing files via email, there are a few best practices organizations and their employees should take into consideration. These include:

Keeping Software and Systems Up to Date

When software and systems are not kept up to date, they are vulnerable to attack. Cybercriminals can exploit known weaknesses in outdated systems to gain access to an organization’s network and data. To help prevent this, organizations need to ensure that all software and systems are regularly updated with the latest edition, which include security patches and other fixes.

Use Strong, Unique Passwords

Using strong, unique passwords is essential for safe file sharing via email. Organizations should establish and enforce policies for password management, such as requiring employees to use complex passwords that contain a combination of uppercase and lowercase letters, numbers, and symbols. Passwords should also be changed on a regular basis and should not be shared with anyone.

Install Antivirus and Malware Protection

Organizations must install and maintain antivirus and malware protection software to help protect against malicious actors. This software should be regularly updated so that it can detect and protect against the latest threats. Employees should also be made aware of best practices for identifying and avoiding phishing emails and other malicious attacks.

Use Multi-factor Authentication

Multi-factor authentication adds an extra layer of security to the authentication process by requiring users to submit two or more pieces of evidence proving they are who they say they are. This could include a combination of something they know (such as a password), something they have (such as a phone or security token), and something they are (such as a fingerprint or facial recognition).

Conduct Routine User Education and Training

Educating and training employees is an important part of maintaining secure file sharing practices. Organizations should provide employees with resources, such as videos and other training materials, on how to securely share files via email. The training should also cover topics such as how to identify suspicious emails or messages and how to protect against phishing attacks. Organizations can also provide employees with security awareness courses or other training opportunities. These trainings should be conducted every year and attendance/completion should be required.

Email Encryption: A Non-negotiable Email Protection Tool

Email encryption is a method of securing the contents of emails that are sent over the internet. This is done by using encryption algorithms to encode the message so that only the sender and the intended receiver can decode and read the message. There are several different methods of email encryption that can be used to protect the contents of emails, and understanding the different methods available is key to choosing the best one for your needs.

S/MIME Encryption

S/MIME (Secure/Multipurpose Internet Mail Extension) is the most widely used email encryption method. It is based on the X.509 public key infrastructure, and is usually integrated into webmail clients such as Outlook and Gmail. It works by encrypting the contents of an email using the recipient’s public key. The sender then signs the message with their own private key, so the recipient can be sure the message has not been tampered with.

PGP Encryption

PGP (Pretty Good Privacy) is another popular encryption method. Unlike S/MIME, PGP does not use any public key infrastructure. Instead, PGP encrypts the message with a symmetric key that is generated by an encryption algorithm. This symmetric key is then encrypted with the sender’s public key and sent to the recipient, who then uses their private key to decrypt the symmetric key and then decrypt the message.

What Is the Difference Between S/MIME and PGP Encryption?

Both S/MIME and PGP are effective encryption methods, but they have some key differences. S/MIME is typically the easier option to set up, as it requires fewer steps and is often integrated into webmail clients. It is also typically more secure, as it uses a public key infrastructure and the message is signed with the sender’s private key. On the other hand, PGP does not require any special software to use, and it is more versatile, as it can be used to encrypt any type of file, not just email messages.

TLS Encryption

TLS (Transport Layer Security) is a protocol that is used to secure communications over the internet, including email. It works by encrypting the data before it is transmitted, so that only the sender and the recipient can decode it. TLS is different from S/MIME and PGP, as it does not use any specific encryption algorithms, but instead relies on the client’s security settings to determine how the data is encrypted. TLS is sometimes used in combination with other encryption methods for added security.

Regulatory Compliance and Secure File Sharing via Email

It is essential for organizations to consider regulatory compliance when implementing email security measures. Many regulations, such as the Health Insurance Portability and Accountability Act (HIPAA), the California Consumer Privacy Act (CCPA), and the EU’s General Data Protection Regulation (GDPR), require organizations to have encryption technology and other email security capabilities in place to protect sensitive information and demonstrate compliance. Failure to comply with these regulations can result in significant penalties, including fines and legal action. Therefore, it is crucial for organizations to ensure that their email security measures align with regulatory requirements to avoid potential risks and consequences.

Email Encryption Gateway With the Kiteworks Platform

The Kiteworks Email Protection Gateway (EPG) is part of the Kiteworks Private Content Network. With Kiteworks EPG, organizations can easily automate email encryption, so it’s invisible to users while still delivering bi-directional email privacy. Recently, Kiteworks EPG supports the S/MIME, TLS, and OpenPGP encryption standards in users’ existing email clients, with end-to-end and gateway encryption options. Kiteworks also provides enterprise-grade encryption, namely AES-256 encryption for content at rest and TLS 1.2 encryption for content in motion, via a Microsoft Outlook plugin, a web app, mobile apps, and various enterprise application plugins.

With Kiteworks, organizations can deliver a private content network (PCN) across all their sensitive communication channels, including email. The Kiteworks-enabled PCN allows organizations to:

Unify secure content communication technologies like secure file sharing, SFTP, managed file transfer (MFT), and secure forms for ease of use and standardized content audit trails. This includes natively extending standard email clients to promote a seamless user experience and protecting every email containing sensitive content sent through these clients.
Track content, metadata, user activity, and system events to boost effectiveness, report on third-party access, and easily meet regulatory compliance reporting requirements.
Control content access and functional rules matched to risk profiles and user roles. Leverage centralized administration to cover emails alongside web forms, managed file transfer (MFT), and secure file sharing for a comprehensive administration experience.
Secure content through encryption of content at rest and in motion, protecting against unintended exposure of sensitive information to malicious actors.

Sending sensitive files over email invites significant risk into the business. Encryption, particularly comprehensive end-to-end encryption in the Kiteworks Email Protection Gateway, goes a long way in mitigating this risk.

Schedule a custom demo to see how Kiteworks can enable your organization to protect sensitive content sent and received over email.

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