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How to Send Password Protected PDF

Protecting your PDFs with a password before sending them is a wise decision. According to data revealed by some of the largest cybersecurity companies, more than 90% of malware is distributed through email services. Electronic messaging companies do their best to make their service as secure as possible, but for now, it is technically impossible to prevent cybercrime from happening. Fortunately, there are secure ways to transfer information by email. In this post, I will talk about how to protect your PDF documents before sending them using the same foolproof security methods that large companies use to protect their information. Before you begin, you should know a few things about the PDF format and the security methods you can use to protect it.

Should I transfer my documents in PDF format?

There are many formats designed for handling text files, but it is a fact that each format excels in different ways.

Currently, PDF is considered the best format for transferring text documents. The reason for this is that this format is compatible with virtually any operating system, guarantees the highest possible quality, and allows you to establish extremely powerful security systems.

All of these virtues are made possible by the sophisticated way information is structured within a PDF. This format stores your resources independently, similar to a folder.

Thanks to this, it is possible to use cryptographic security systems that allow restricting access or certain document characteristics.

How can I protect my PDF document?

The most recommended is to use specialized cryptography mechanisms for digital data. Cryptography is the field of cryptology devoted to encryption techniques that prevent unauthorized persons from viewing a message.

In computing, information is made up of binary values (bits). Thanks to this, it is possible to use encryption techniques that generate a cryptographic key and an algorithm that stipulates the original document's binary value as a result.

How is the process of encrypting a PDF?

A fragment of the original document and a cryptographic key, both 128 bits, are used during an encryption process.

Subsequently, an operation based on the operation of the logic gates (A XOR B) is performed. The rest of the information in the document is segmented using the result of this equation to create a matrix with which the segments and their values will be reassigned in a chaotic but reversible order, as long as the cryptographic key is available.

A password is usually made up of 128 bits, and most of the applications that generate them use a value assigned by the user as a reference; These cryptographic keys are known as passwords, and to replicate their value without knowing the password, it would be necessary to try different combinations until the correct combination is found. For this, it has to be considered that each bit can represent two values (1 and 0); therefore, "2" must be multiplied by itself 128 times (2 ^ 128).

On the other hand, you should keep in mind that brute-force attacks could find out the value that the user assigned as a password. To ensure that your password is secure, you should keep in mind that each additional character the password has, makes it exponentially stronger.

Part 1. How to Protect Your Private Information before Sending

Now you know how cryptographic security systems work and how they can protect a PDF document, but you probably still have questions about how to protect your PDF documents. The first thing you need to know is that you will need to use specialized tools to protect your PDFs. You can use several tools to protect your documents, but one allows you to have all the protection tools in the same place. It's called PDFelement, and I'll show you how to use it below.

Method 1.Password

As I told you earlier, a password-encrypted system is a foolproof security measure. Thanks to PDFelement's advanced encryption technology, you can selectively encrypt the features you want, which will help transfer PDFs much easier and surely with other tools. Now I will show you how to do this.

Step 1: Open your PDF

The first thing you need to do is open your PDF using PDFelement. You can do this by right-clicking on your document, pulling down the "Open with" menu, and selecting PDFelement, or you can also open the application and click the "Open files" button.

open your pdf

Step 2: Open Set Password tool

Once your document is open, go to the "Protect" section and click on the "Set Password" button. This will display a pop-up showing some of the available security features.

open set password tool

Step 3: Set a Password

In this window, you will find two options to encrypt your document and restrict access to specific features. The first option, "Open password," will allow you to assign a password that makes it impossible to open the document unless the correct password is entered. When you have established it, click on "Save".

set a password

Method 2. Redact

Redacting your document is a sensible way to hide sensitive data permanently. This may not be feasible in some cases, but if you don't have a problem with this information disappearing from the document, you should try it, especially if it has sensitive data that you don't want to share.

Step 1: Go to “Mark for Redaction”

Once you have your document open with PDFelement, go to the Protect section and click on the "Mark for Redaction" option. This will enable your cursor to select areas of the document. Next, select the areas of the document that you want to hide.

mark for redaction

Step 2: Confirm the Redaction 

Once you have finished selecting all the document areas that you want to hide, go to the "Apply Redaction" option located in the same toolbar where you found the "Mark for Redaction" option. You will see a pop-up asking for your confirmation to apply the changes.

confirm the redaction

Method 3. Read-only

Suppose you need to share a PDF document for the recipient to sign the document or make comments without editing privileges. This is very common when working with documents of a legal or financial nature. Fortunately, this is possible using PDFelement's specialized encryption tools. Now I'll show you how it's done.

Step 1: Restrict Permissions

Reopen the "Set Password" tool found in the "Protect" section and, this time, enable the "Permission Password" option. Below you will find two options to use their drop-down menus to set the restrictions you need. When you finish, click on "Save".

restrict permissions

Method 4. Sign

Signing a document is a very common way to stipulate contribution, authorship, or consent, and PDFelement has a tool that allows you to add signatures to your document. Remember that cryptographic locks can protect all the resources that make up a PDF; this means that once you place your signature, it will be impossible for someone not authorized to modify it. Now I will show you how to sign your documents.

Step 1: Open the Sign tool

The first thing you should do is go to the "Comment" section and click on the pen icon located at the far right of the bar. This will display a menu to choose one of the signatures you have previously created or create a new signature. Click on "+Create".

open sign tool

Step 2: Create a Signature

Now you will see a window with a canvas where you can trace your signature, but you can also enter a signature using only your keyboard or upload an image. When you're done, click "OK" and select where you want to place your signature on the document.

create signature

PDFelement is an all-in-one PDF tool with many powerful features apart from file safety. Click the video below to know more.

Part 2. How to Send Password Protected Email via Gmail

All you have to do is make sure that your means to send your documents are secure. If you're going to use your email to send these documents, there are a couple of tips to consider to ensure everything is under control.

Tip 1. Use Confidential Mode

Gmail has a feature called "Confidential Mode." This feature allows you to set a deadline to access the document, and you can access it by clicking on the lock icon with a clock located between the message editing tools.

use confidential mode

Tip 2. Password-Protect Gmail Attachments

Another notable feature of the "Confidential mode" is an option that allows you to generate confirmation codes by two factors. This tool will request a key auto-generated by Google every time you open or download the document.

sms passcode


Protecting your PDF documents is a wise decision. Data leakage is an increasingly frequent problem and can lead to many other serious problems. Fortunately, there are tools and services like PDFelement or Gmail that can help you protect your documents, using state-of-the-art encryption techniques that guarantee that no one will ever be able to access your information. It is enough to make a few clicks to guarantee the security of your information.

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