Cover your tracks: the risk of sending unencrypted files

Whether for work or personal use, file sharing is a vital part of how we interact with each other on the internet. While most of your day-to-day file sharing might just be funny animal pictures, we sometimes send and receive files containing critical information – sensitive work documents, private financial records, personal health data, and so on.

It’s immediately apparent how important these files are, but most people don’t take the time to do the extra security work to make sure they don’t fall into the wrong hands. Without encryption, you’re vulnerable to cyber threats and potential data breaches.

Read on, and I’ll discuss some of the risks of unencrypted file sharing, as well as a few actionable tips you can adopt in your daily life for securing your digital communications.

Unencrypted file sharing: the risks

Before you can understand why sending files unencrypted is risky, it’s best we go through the basics of how encryption works.

Encryption is the process of converting a piece of data that a computer can easily read into unreadable gibberish. Anyone who looks at the encrypted data can’t tell what it contains.

The only way to turn the scrambled data back into the original file is with a specific key. You can think of it as a password. Without encryption, a file stays in the same form while it’s sent over the internet, making it accessible to anyone who intercepts the internet traffic during transmission.

When files are shared without encryption, they become highly vulnerable to interception. Cybercriminals, governments, and your ISP can potentially read the unencrypted files you send if they have access to a device that your traffic is being routed through.

This could be a rogue Wi-Fi access point in the case of a hacker or the network infrastructure you use to connect to the internet in the case of your ISP.

Additionally, if the files you send are stored on an insecure server or cloud hosting platform, hackers may be able to gain access to them through a backdoor or using weakly secured credentials.

Failing to encrypt sensitive files can lead to severe consequences:

• For example, sending a picture of your government-issued ID through an insecure channel could leave you open to identity fraud, as cybercriminals can use stolen personal data to open fraudulent accounts in your name or gain access to sensitive online services using your ID as proof of identity.
• There’s also the threat of financial loss, as leaked records, credit card details, or banking information can give hackers the ammunition they need to carry out targeted fraud on either yourself or others with whom you do business.
• Businesses that do not encrypt confidential files also risk severe data breaches, which can lead to reputational damage, legal consequences, and financial penalties.
• Worst of all, some automated systems can intercept your files mid-transmission and dynamically infect them with malware, creating a spearphishing attack on the recipient that you’re unwittingly complicit in.

What else can you do to protect your file-sharing?

There are a few ways you can keep outside snoopers from capturing your files – but one way or another, you need to make sure the traffic that they observe is encrypted.

Secure file transfer
You could use a secure file transfer method, which encrypts the tunnel used to send your files to another device. While FTP is insecure, SFTP upgrades the protocol by using a secure channel to send files back and forth.

This secure channel is usually SSH, but it can also use TLS or other encrypted tunnels to protect the data.

Transferring data using HTTPS also keeps your traffic from being read. This is especially useful when used in tandem with encrypted cloud storage, as you know that your data hasn’t been read in transit and is stored in an online enclave that only you can access.

VPN
You can also use one of today's best VPN solutions, but you need to be particular about which one you choose. A consumer VPN typically only encrypts your traffic until it reaches the VPN servers – after that, the VPN encryption is stripped so the device at the intended destination can read your traffic and respond.

However, a corporate VPN provides effective end-to-end encryption if you’re transferring files to and from your workplace servers.

Cloud storage
Picking a cloud storage provider you trust is essential, but it’s also important to enable as much security as possible. All the fancy encryption algorithms in the world are worthless if it’s easy to get into your cloud file sharing account.

This is why you need to make sure you have two-factor authentication enabled on all of your accounts. This security measure requires you to provide two different types of authentication, such as a password and an SMS code, before accessing files.

Yes, it’s a little annoying having to grab your phone or an authenticator every time you want to get into your account, but you’ll be relieved you enabled it if you ever get a notification telling you that someone unsuccessfully tried to access your files.

Encrypt before sending
Encrypting your files before you send them is another way of ensuring their security, but it comes with caveats.

Symmetric encryption algorithms allow you to encrypt and decrypt files with the same key. They’re also fast and use relatively fewer system resources, so they’re ideal for file encryption.

However, if you’re sending a file to another person, you need to make sure you’re sending the key in an encrypted way; otherwise, anyone monitoring your traffic will be able to intercept both the encrypted file and the encryption key.

This is where asymmetric encryption comes into play: while slow, it ensures that the file you encrypt with someone’s public encryption key can only be decoded with their private decryption key.

If you need to establish a secure channel with someone else, you can trade public keys to create an encrypted tunnel and then share a symmetric key over that tunnel, which encrypts the bulk of your data.

You can replicate this in a makeshift way by encrypting your file with a file encryption program and then sending your symmetric encryption key over a secured line of communication that has already been established, like Signal.