File Encryption

Key Takeaways

• File encryption protects data, ensuring only authorized access via a decryption key.
• Symmetric encryption uses a single key for encryption and decryption, offering speed and efficiency but posing risks if the key is compromised.
• Asymmetric encryption involves a public key for encryption and a private key for decryption, providing enhanced security but requiring more computational resources.
• Advances in encryption technologies, like quantum cryptography and passwordless authentication, promise stronger and more user-friendly security solutions.

Every day, we exchange countless files. Finance Online provides a glimpse of the amount of files and data 4.4 billion internet users produce daily. Each one holds a piece of our lives. Without encryption, these files are open invitations to digital thieves. Imagine your bank statements, family photos, or work projects exposed. Scary, right? File encryption locks down your data using encryption software, keeping it safe.

Let’s explore file encryption in more detail. We’ll learn what it is, how it works, and the different ways your information is protected.

What Is File Encryption?

Whenever you send a file over the internet, it changes into a code or cipher to protect it from unauthorized access. This process, known as file encryption, encodes your files and the sensitive data they contain during file transfer or storage. It means that even if a third party intercepts or steals your file, they cannot read the data. File encryption relies on public key cryptography.The sender encrypts the data with a public key, and the receiver decrypts it with a private key, keeping the information secure during transmission.

These key pairs work like a lock and password system, ensuring that only the intended sender and receiver can access the data. Our comprehensive explanations of public and private keys provide valuable insights into how file encryption works and how it ensures data security.

What is File Encryption Used For?

When confidential files go online or are on portable devices, file encryption makes them unreadable unless you have the right key or password. Data protection makes file encryption an indispensable technology for businesses, organizations, and individuals handling sensitive data.

Beyond protecting individual data, file encryption is also vital for global IT and cybersecurity. Consider the devastating consequences of a data breach. Hackers with ransomware could damage businesses by accessing unprotected files. Plus, it could be catastrophic if the wrong people get their hands on sensitive data. Leaking patient records, private images, or confidential business information could lead to chaos, like reputation damage and financial loss.

It is als worth mentioning full disk encryption, which secures an entire disk or drive but doesn’t encrypt individual files within the disk. It’s wise to use file encryption and full disk encryption simultaneously for extra security, so that both your hard drive and your individual files are protected.

Some companies are encrypting their sensitive data in the cloud, but they’re the minority. Storing encrypted files in cloud applications can be more complicated.

Different Types of Encryption

There are different approaches to encryption, both of which use keys to encrypt and decrypt data. However, they take distinct approaches and offer varying security levels.

File encryption protects individual files or file systems by encrypting them with a specific key, making them accessible only to the keyholder. The goal is to prevent malicious or unauthorized parties from accessing files that are stored on the disk. Support for file encryption can be built into an operating system or file system. A decryption key allows access to the sensitive files. File encryption is helpful if a user needs to send individual files securely over the internet or store them on a removable device such as a USB stick. A file in transit is sometimes referred to as data in motion.

Symmetric Key Cryptography

Symmetric encryption is an encryption system in which both the sender and the receiver share the same key. Think of it as a unique puzzle piece that fits into a specific lock. To send a secure message, you transform your original message into a scrambled version using a puzzle piece. The recipient then uses the identical puzzle piece to unscramble the text, revealing the message.

Let’s say Brian and Sean want to organize a confidential meeting using a secret key. They decide to use a specific book as their shared secret key. Brian wants to send the message “Meet at dawn” to Sean. 

He first converts each letter of his message into a number corresponding to its position within the book, such as page, line, and word number, creating a numerical code. Brian then transmits this numerical code to Sean. Sean, who also has access to the same book, uses the numbers to locate the corresponding letters in the book and reconstructs the original message “Meet at dawn.”

While effective, symmetric key encryption hinges on securely sharing the secret key. If this key falls into the wrong hands, the encryption is compromised – whoever has it can read the private conversation, alter messages and even contribute their own messages undetected. This is known as a man-in-the-middle attack. 

This limitation underscores the importance of proper key management practices.

Advantages of Symmetric Key Encryption

Symmetric key encryption is a popular choice for securing data thanks to its impressive speed. Because it uses the same key for encrypting and decrypting, it can zip through large files efficiently. Its swift action makes it a top pick for handling large data loads quickly.

Another perk is its efficiency. Symmetric encryption demands little computing power, which is great for devices with limited resources, like smartphones or smart home gadgets. Less energy spent means better battery life for everyone.

Symmetric encryption’s other strength is keeping things simple. It is easy to understand and implement, making it a practical option for various applications.

Risks of Symmetric Key Encryption

• Encryption key is vulnerable during transmission
• Single point of failure
• Poor key storage compromises security

While offering speed and efficiency, symmetric key encryption presents significant challenges. Securely distributing the encryption key to all parties involved poses a major hurdle. If someone intercepts this key during transmission, they will gain unauthorized access to encrypted data.

Moreover, symmetric encryption operates as a single point of failure. If the key is lost or compromised, all data protected by that key becomes vulnerable. This risk increases when multiple parties share the same key, as a breach affecting one party compromises communication for all.

Properly storing the secret key is also vital. Its theft renders encrypted data accessible to malicious actors. Reliable security measures must safeguard the key to prevent catastrophic data breaches. Unlike asymmetric encryption, symmetric encryption lacks non-repudiation, making it difficult to verify the sender of a message, a critical limitation in specific contexts.

Use Cases

Various digital applications employ symmetric key encryption.

• Financial infrastructure uses symmetric encryption to secure sensitive financial data, such as card information, during transactions.
• The internet depends on symmetric encryption. Protocols like SSL and TLS employ it to secure data transmission, ensuring privacy during online banking and website logins.
• Virtual Private Networks (VPNs) also leverage symmetric encryption to protect data as it travels between devices and VPN servers.
• Hardware devices like encrypted USB drives and self-encrypting hard drives incorporate symmetric encryption to protect data in case of device loss or theft.

Public Key Cryptography (Asymmetric Encryption)

Public key cryptography employs a pair of keys: a public and private key. To illustrate, consider Tom wanting to send a secret menu to Mindy. Tom encrypts the menu using Mindy’s public key, which only Mindy can decrypt with her private key. This process begins with Mindy generating a public-private key pair. 

She distributes her public key freely while securely safeguarding her private key. Tom receives Mindy’s public key to encrypt the menu, transforming it into unreadable ciphertext. He sends this ciphertext to Mindy. 

Upon receiving it, Mindy uses her private key to decrypt the ciphertext, recovering the original secret menu. Only Mindy possesses the private key, ensuring the message’s confidentiality.

Advantages of Asymmetric Key Encryption

Asymmetric key encryption provides several advantages.

• Asymmetric encryption employs a public key for encryption and a private key for decryption. Separating the public and private keys reduces the risk of unauthorized access, as the private key remains confidential.
• Unlike symmetric encryption, asymmetric encryption freely distributes the public key. It makes starting secure communications easier.
• Asymmetric encryption allows for digital signature creation. Senders authenticate their identity and confirm message integrity by signing with their private key, and recipients can verify the signature with the sender’s public key.

Risks of Asymmetric Key Encryption

While offering unique advantages, asymmetric key encryption also presents significant challenges. Its computational intensity is a primary drawback.

The complex mathematical operations underpinning encryption and decryption demand substantial computational resources, resulting in slower performance than symmetric encryption.

Asymmetric encryption relies on protecting private keys. If compromised, it threatens the security of all communications encrypted with the corresponding public key.

Key management complexity further characterizes asymmetric encryption systems. Public key distribution is relatively easy, but private key storage and management require advanced security measures. Also, verifying and authenticating public keys to prevent man-in-the-middle attacks adds more sophistication to the system.

Use Cases

Many applications rely on asymmetric key encryption to keep communication and data safe.

• Secure email services like PGP leverage public key cryptography to encrypt messages, ensuring only intended recipients can decrypt them. S
• SL/TLS protocols, which safeguard web traffic, rely on asymmetric encryption to establish secure connections between browsers and web servers, protecting transmitted data.
• Digital signatures, another critical application, verify the authenticity and integrity of documents, software updates, and other sensitive information.
• Organizations employ private keys to sign documents, assuring recipients of the content’s unaltered origin from a trusted source.

Asymmetric encryption also powers cryptocurrencies like Bitcoin, where public and private key pairs manage digital wallets and secure transactions. Public keys serve as receiving addresses, while private keys authorize fund transfers, guaranteeing only wallet owners can spend their digital assets.

Which files do you need to encrypt?

Sensitive files are like your poker strategy – they’re valuable, and you want to control who sees them. Unfortunately, not everyone plays fair. Hackers are always looking out for opportunities to steal your data.

So, what kind of files need extra protection?

• Personal details: Social security numbers, passport numbers, driver’s licenses, and other personal identifiers.
• Money-related information: Credit card numbers, bank accounts, tax returns – basically, anything related to your or your client’s finances.
• Health matters: Medical records, prescriptions, and insurance info are all private and need extra care.
• Legal data: Contracts, agreements, and confidential legal documents can make or break a deal. Keep them safe.
• Employee information: Salaries, performance reviews, and contact details.
• Everyday communication: Emails can contain sensitive info, so it’s smart to encrypt them.
• Your intellectual property (IP).

When Should Encrypted Files Be Used?

So, you’re considering encryption. Great! It’s a solid way to keep your data safe. But when is it really necessary? Let’s break it down.

Transmission Over a Network

When your data travels on any network, it’s like sending a postcard. Anyone can read it. Encryption is like putting it in a locked envelope. Only the intended recipient can open it. Always encrypt your data when it passes over a network. 

Data in Active Use

Imagine your data as a recipe. To cook it, you need to read it. But while you’re reading, someone could steal it or take a sneak peek. Encryption is like keeping the recipe locked until it’s time to use it. This is a complex process but offers the highest security level.

Archived Data

Just because data is idle on a hard drive doesn’t mean it’s safe. Encryption adds an extra protection layer by making the data inaccessible without the correct key. Encryption will safeguard sensitive information stored on servers or local devices.

How to Encrypt a File?

Numerous built-in and third-party tools simplify file encryption on computers and smartphones. Let’s consider them below.

Encrypt Files on Windows

Microsoft offers built-in tools for file encryption, such as BitLocker. Here’s how you can encrypt your data:

• Built-in Encryption: Right-click the file/folder, choose Properties > Advanced > check Encrypt contents to secure data and confirm.
• Third-Party Options: Explore tools like VeraCrypt for advanced encryption features.

Encrypt files on Mac

MacOS also provides built-in tools for file encryption. If you want to use it yourself, here are the steps to follow:

1. Open Disk Utility (Finder > Applications > Utilities).
2. Click File > New Image > Image from Folder.
3. Choose the folder you want to encrypt and click ‘hoose.
4. Select your level of encryption and set a password.
5. Click Save and wait for the encryption process to finish.

Encrypt Files on Android

Android devices offer a combination of built-in and third-party options for file encryption.

• Built-in Encryption: While Android devices come with built-in encryption for the entire device, this doesn’t directly encrypt individual files. To enable device-wide encryption, go to Settings > Security and look for the option to encrypt your device.
• Third-Party Apps: Androids also allow dedicated encryption apps to encrypt specific files or folders. These apps often allow you to set passwords or PINs for added security.

Encrypt files on iPhone

Data protection on iPhones depends mainly on device-level encryption.

• Device Encryption: By setting a strong passcode on your iPhone, you activate encryption that protects most of your data. Go to Settings > Face ID & Passcode, or Touch ID & Passcode for other models, to set or change your passcode.
• Third-Party Apps: While less common than on Android, third-party apps like Encrypt.me offer file-level encryption options. Additionally, built-in apps like Notes and Photos provide encryption for specific features like password-protected notes or hidden albums.

The Future of File Encryption

Beyond innovations like quantum key distributions and post-quantum cryptography, there are improvements that we experience daily. Let’s look at passwordless and keyless authentication and its benefits.

Improved User Experience

Complex passwords and frequent changes hinder user productivity in traditional systems. However, using passwordless authentication, as is the case with encryption systems, streamlines access by eliminating these burdens.

Cost Reduction

IT departments expend significant resources managing passwords and keys. For example, assword resets, inquiries, and rotations all consume staff time, while key management is complex and inefficient. Conversely, passwordless and keyless authentication reduces IT overhead and costs.

Enhanced Security

Passwordless and keyless authentication strengthen security by removing vulnerable passwords and keys, reducing theft risk.

Closing Thoughts

As technology advances, encryption practices will continue to protect our digital lives, ensuring privacy and security in an increasingly connected world. With encryption now an omnipresent part of our daily lives, it pays to know exactly how it works – and how your precious data is secured.

About the author

Sal Miah

Sal is a seasoned writer with a deep expertise in blockchain, cryptocurrency and the ever-evolving Web3 landscape. Since 2018, Sal has crafted content for several blue-chip organizations, drawing on a strong foundation in finance and trading to bring clarity and insight to complex topics.

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