How to Edit and Send Documents Securely via Text Message

Feb 28, 2025

Did you know that about 23 billion text messages are sent every day?

Whether it’s a cute photo of your dog, a quick ‘hi!’ to your friend, or an important file, millions of messages are sent every single minute… 

However, we’re willing to bet that a fair few of those text messages aren’t encrypted. And sending sensitive files through standard SMS is about as secure as mailing a postcard—so anyone with the right tools can intercept them.

Convenience should never come at the cost of security, especially when there are tools that help you encrypt, protect, and send files safely (without taking time out of your day!). With secure messaging apps and editing tools such as PDFinity, you can make sure your information stays private before hitting ‘send.’

In this article, we’ll break down the risks of sending files via text, how to choose the right secure messaging and editing tools, and how to properly encrypt your documents before sending them.

The Risks of Sending Files Via Text Message

There’s no doubt that text messages are fast, easy, and widely used—after all, millions rely on them for day-to-day communication. But when it comes to sending sensitive documents, it’s also one of the least secure methods available.

Let’s take a look at some reasons why: 

  • Standard SMS is NOT encrypted – If you send a document through regular SMS, it’s vulnerable to interception by hackers, mobile carriers, and (in rare cases) government agencies.
  • MMS has additional risks – Although MMS (Multimedia Messaging Service) allows for file attachments, it compresses images and files and may store them on a carrier’s servers, which exposes them to security risks.
  • Wrong recipient – Have you ever accidentally sent a message to the wrong number? Once a file is out in the wild, you can’t unsend it.
  • Prone to phishing – If you’re on public Wi-Fi, attackers can sniff out unencrypted messages and expose private information.

Even tech companies with strong security measures aren’t immune to these kinds of attacks, which often begin with a simple text. In late 2022, several Zendesk employees were targeted in a “sophisticated SMS phishing campaign” where sensitive data was made available to an unauthorized party.

This example is also why you should think twice before sending confidential files (such as contracts, medical records, and financial data) via a standard text. If hackers gain access to your information, they can sell it, leak it, or use it to launch further attacks—all from a simple, unsecured text message!

Choosing The Right Tools

Not all apps and tools are created equal—especially when it comes to security. Some encrypt all conversations and attachments by default, while others require you to manually enable additional security settings.

For example, Signal is often considered the most secure messaging app and offers strong encryption, disappearing messages, and no cloud backups, making it the best option for those prioritizing privacy.

Telegram is another solid choice, but only their ‘Secret Chat’ feature offers end-to-end encryption (you’ll have to manually enable this mode before sending sensitive documents). 

WhatsApp uses end-to-end encryption (E2EE) by default, ensuring that messages and files remain private, while Apple’s built-in iMessage app is encrypted (but their iCloud backups can be vulnerable).

Besides choosing the right texting app, it’s just as important to use the right document tool.

For example, PDFinity allows you to password-protect PDFs before sharing them. Instead of sending an unprotected file, you can generate a secure document that requires the recipient to enter a unique 4-digit code to access it. That way, even if someone else gets their hands on the message, they won’t be able to read the file without the code.

How to Secure Documents Before Sending Via Text

Before hitting that ‘send’ button, it’s worth taking a few extra steps to protect those sensitive files.

Many files, images, and PDFs contain hidden metadata that can reveal more than you intend. This often includes details such as your name, location data, version history, and even device information. While this may not seem like a big deal, it can pose serious security risks.

For example, a photo may store GPS coordinates, revealing exactly where it was taken. A business contract may contain hidden edits or tracked changes, exposing previous negotiations or private notes. If this information falls into the wrong hands, it could compromise confidentiality and security—so always double-check the metadata and strip it if necessary. 

Speaking of images… If you’re sharing photos, blueprints, contracts, or proprietary designs, adding a watermark is one of the best ways to prevent unauthorized use. Watermarks help prevent unauthorized sharing and can also track the origin of a document if it’s leaked.

Likewise, consider the way you send documents. One of the safest ways to share a file is to send it as a link instead of an attachment. Some services allow you to restrict access permissions so that only the intended recipient can view or download the document. 

Last but certainly not least, avoid sending highly sensitive data via text message whenever possible. If you really need to share documents containing sensitive or personal details, look for services that offer end-to-end encryption, password-protected file access, and temporary download links to ensure that only the intended recipient can open the file.

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