How to Encrypt Your Files on the Computer: Essential Security Guide

Encrypting files means making them unreadable without a key. It is a basic file security measure that protects your privacy even if you lose the device.

Today, more than ever, learning how to encrypt files on a computer is part of any digital protection strategy.

Why is it important to encrypt files?

Losing the computer should not mean losing your privacy.

Imagine you are traveling by train with your laptop. You fall asleep for a few minutes. When you wake up, it’s gone. You haven’t just lost a device. You’ve lost access to sensitive documents that could be in anyone’s hands.

Inside there were:

• Confidential work reports.
• Personal photographs.
• Invoices with bank details.
• Tax documentation and contracts.

Without encrypting files, that information can be opened in a matter of minutes. You don’t need to be an expert. Just turn on the device and access the disk.

The risks of not protecting your data are very real:

• Physical theft of the laptop in transit or public spaces.
• Unauthorized access in shared offices.
• Loss of external drives or USB sticks.
• Targeted attacks on corporate equipment.

Disk encryption or folder encryption completely changes the scenario. When you apply encryption:

• The data becomes inaccessible without a password.
• Even if someone has physical access, they cannot read the content.
• You can reduce the risk of leakage after a theft by up to 90%.

Encrypting does not prevent your device from being stolen. It prevents your information from being used.

What does it mean to encrypt a file or folder?

Encrypting means converting readable information into an incomprehensible format using mathematical algorithms. In other words, the data becomes meaningless if you do not have the correct key.

Without the correct password, the file simply cannot be used. It’s like having a safe without a combination.

A practical example makes it clear:

• A Word document turns into unreadable symbols.
• An image cannot be viewed.
• A video does not play.
• A program does not run.

The file is still there, but it is useless to anyone without authorized access.

It is also important to distinguish the different levels of protection. Encrypting a file is not the same as applying full disk encryption.

• File encryption: protects specific documents, one by one.
• Folder encryption: protects an organized set of files.
• Full disk encryption: protects the entire operating system and all stored data.

Disk encryption offers the broadest coverage, as it protects the entire device. File encryption, on the other hand, is more selective and allows you to protect only confidential information.

Methods integrated into the operating system

Many users do not know it, but their own system already includes options to encrypt files without installing external programs.

These native tools allow you to apply folder encryption or full disk encryption with a few steps and good integration with the system.

They are especially recommended if you are looking for:

• Simplicity.
• Stability.
• Total compatibility with your device.
• Official manufacturer support.

Let’s look at each case.

Encryption in Windows

In Microsoft Windows, there are two main methods.

EFS (Encrypting File System) allows you to encrypt individual files from the properties menu.
It is useful if you only need to protect specific documents.

Advantages:

• Quick activation.
• Does not require special partitions.
• Ideal for selective encryption.

Limitations:

• Only available in Pro and Enterprise versions.
• Does not protect the entire system.
• Depends on the user who encrypted it.

For stronger protection, Windows includes BitLocker, which applies full disk encryption. This means that all the content on the device is protected.

Key features:

• AES encryption with hardware acceleration.
• Integration with TPM (Trusted Platform Module).
• Exportable recovery keys.
• Centralized management in enterprise environments.

It is the most recommended option for work laptops or devices that leave the office.

Encryption in macOS

In macOS, the integrated solution is FileVault, which allows you to activate full disk encryption with a single click from System Preferences.

Key points:

• XTS-AES-128 or AES-256 encryption.
• Total integration with the user account.
• Recovery via Apple ID or generated key.
• Minimal impact on performance (less than 5% on modern devices).

For Mac users, it is the simplest and most effective way to protect files with a password without installing additional software.

Options in Linux

In Linux, the most widely used standard is LUKS, which allows you to apply full disk encryption during system installation or later.

Main features:

• Support for multiple algorithms.
• Advanced key management.
• Integration with tools like dm-crypt.
• High technical customization.

Linux offers great flexibility but requires more advanced knowledge.

Recommended encryption tools

If your system does not include sufficient options, there are specialized programs to encrypt files.

TrueCrypt

TrueCrypt was for years a reference in the world of encryption. It popularized the use of encrypted volumes and the concept of password-protected “containers.”

However, the project was discontinued in 2014. Although it is not recommended to use it currently, its technical legacy gave rise to VeraCrypt, which fixed vulnerabilities and strengthened its security.

VeraCrypt

VeraCrypt is one of the best tools for encrypting data currently available and is the direct successor to TrueCrypt.

It allows you to:

• Create encrypted volumes within files.
• Encrypt entire partitions.
• Apply full disk encryption to the operating system.
• Use robust algorithms like AES, Serpent, or Twofish.

It is cross-platform (Windows, macOS, and Linux) and free.

Its main advantage is the high level of configurable security. It allows you to define algorithms, number of iterations, and advanced authentication systems.

It is ideal for users seeking advanced security without relying on the operating system.

Other alternatives

In addition to the most well-known tools, there are other interesting alternatives for encrypting files depending on the type of use you need.

• AxCrypt: is a simple solution for protecting files with a password on Windows. It allows you to encrypt individual documents with a few clicks and offers integration with cloud storage. It is ideal for users looking for speed and ease of use without complex configurations.
• Cryptomator: is specially designed to protect files stored in services like Dropbox or Google Drive. It creates an encrypted vault before the data is uploaded to the cloud. It is an excellent option if you are concerned about file security in cloud environments.
• Sophos (enterprise solutions): offers advanced disk encryption and endpoint protection tools. It is aimed at companies that need centralized control, regulatory compliance, and security policies managed from a corporate panel.

Each tool responds to a different need. If you are looking for personal use, simplicity, and speed, AxCrypt may be sufficient. If you work with cloud storage, Cryptomator provides an extra layer of protection. And if you manage multiple devices in a company, professional solutions allow you to scale encryption securely and controlled.

Tool	Type of encryption	Platform	Recommended level
EFS (Windows)	Individual file encryption	Windows Pro/Enterprise	Basic personal use
BitLocker	Full disk encryption	Windows Pro/Enterprise	High (enterprise and professional)
FileVault	Full disk encryption	macOS	High (integrated and optimized)
LUKS	Full disk encryption	Linux	High (technical users)
VeraCrypt	Encrypted volumes and full disks	Windows, macOS, Linux	Very high (configurable and advanced)
TrueCrypt	Encrypted volumes and full disks	Cross-platform	Not recommended (discontinued)
AxCrypt	Individual file encryption	Windows, macOS	Medium (simple use)
Cryptomator	Encryption for cloud storage	Windows, macOS, Linux	High (cloud protection)
Sophos (Enterprise)	Disk encryption and centralized management	Corporate environments	Very high (enterprise)

Best practices when using encryption

Encryption is only as strong as your password and key management. A poor configuration can nullify all protection.

1️⃣ Use strong and secure passwords

A weak password makes encryption a useless formality.

Clear recommendations for creating a secure password:

• More than 12–16 characters.
• Combine uppercase, lowercase, numbers, and symbols.
• Avoid dates, proper names, or predictable patterns.
• Do not reuse passwords on other services.

Pro tip: use long phrases that are easy to remember but challenging to guess.
Example: BlueMountain!2026Wind.

If you use advanced tools like VeraCrypt or full-disk encryption, also consider enabling multi-factor authentication if available.

2️⃣ Make backups before encrypting

Never encrypt without a prior backup.

A power outage, disk failure, or poor configuration can block access to the data. And in encryption, there is no “undo” button.

Best practices:

• Make a copy on an external drive.
• Verify that the copy opens correctly.
• Keep at least one copy disconnected from the device.

Remember: encryption and backup are complementary, not substitutes.

3️⃣ Secure storage of recovery keys

Without a key, there is no possible recovery.

Modern encryption is designed to be irreversible without the correct password. That is its strength… and its risk.

Where to store the key:

• In a secure password manager.
• In a physical copy stored in a protected place.
• In an external device also encrypted.

Never store it in an unprotected file on the same computer.

Threats and security considerations when encrypting

Encryption protects against unauthorized access, but it is not a magic solution.

Risks if the password or recovery key is lost

• The data becomes permanently inaccessible.
• There is no technical support capable of recovering them.
• Not even the manufacturer can break the encryption.

That is why key management is as important as encryption itself.

Possible performance impacts

On modern devices, the impact is usually less than 5%.

On older computers, it may be noticeable:

• Slower boot.
• Slightly heavier disk access.
• Higher CPU consumption in intensive tasks.

Even so, the cost in performance is minimal compared to the benefit in security.

Prevention against ransomware and malware that encrypts data

Encryption protects against physical theft or unauthorized access. It does not always protect against active ransomware.

If malware encrypts files while you are connected and authenticated, it can also affect decrypted data.

Additional recommended measures:

• Keep the system updated.
• Use active antivirus and firewall.
• Perform periodic offline backups.
• Do not run suspicious files.

Real security is multi-layered.

Practical use cases

Encryption is not just for tech experts.

Users who work with sensitive information (finance, work)

• Financial data.
• Client information.
• Contracts and legal documentation.
• Business projects.

For freelancers and professionals, encrypting files reduces legal and reputational risks.

Professional and personal use: laptops, external drives, USB

Common applications:

• Laptops that travel with you.
• External drives with backups.
• USB sticks with important documents.
• Shared devices in family environments.

Folder encryption is useful in home environments. Full-disk encryption is more suitable for mobility.

Small businesses and data protection compliance

Encryption helps comply with data protection regulations like GDPR.

Clear benefits:

• Minimizes impact in case of device theft.
• Reduces legal liabilities.
• Strengthens customer trust.

In many security audits, encryption is a basic requirement.

Conclusion

Encrypting files is a basic digital protection measure. It is not an advanced option. It is an essential practice.

Today we store on the computer:

• Financial information.
• Personal data.
• Professional projects.
• Access to online services.

Without encryption, all of that is exposed to theft, loss, or unauthorized access.

When you apply disk encryption or folder encryption:

• You protect your privacy.
• You reduce the risk of leaks.
• You strengthen your security against physical incidents.
• You better comply with data protection regulations.

The question is not whether you can afford to encrypt your files. The question is whether you can afford not to.

Start today:

1. Check if your system has BitLocker, FileVault, or LUKS activated.
2. Install a tool like VeraCrypt if you need more control.
3. Protect at least the folders containing sensitive information.
4. Properly store your recovery key.

Encrypting files is taking control of your information. And in an increasingly exposed digital environment, that makes the difference.