So you have a mobile phone, tablet and a laptop, but the file you need to view on your phone is saved on the laptop's hard drive. Fortunately, apps and cloud services that can sync (synchronize) files between mobile devices and computers are readily available. If you keep your devices synced, you can always have all your files with you. Sounds good, but there are so many downsides and risks with sync that we don't do it at all. Here is why.

All products and services that promise to sync files and data don't have the same functionality. The traditional meaning of the word "synchronize" in computing is defined in a dictionary as "to configure (two or more electronic devices) so that any changes to the data held on one device are also implemented on the other(s)". When you sync, for instance, your phone and laptop it is a two-way process where the result is that both devices have the same data.

Nonetheless, many products can only do one-way sync: upload or download. One-way sync is safe because it avoids the fundamental problem inherent in two-way sync: if both devices have the same file, what should the sync program do? There is no universal, absolutely correct solution for this.

Why we don't sync

Three reasons why we don't sync our PCs and mobile devices are high security risks, difficult management of data integrity and additional storage space requirements.

Security

When files and other data are copied, or synced, to multiple devices, securing that data becomes more difficult. Especially mobile devices can be lost or stolen. Sensitive or confidential data on devices that end up in wrong hands must be assumed accessed. Modern mobile operating systems allow encrypting of all data on a device, but encryption is not always activated.

Another high risk item in mobile devices is apps that are used to access cloud services, file storage, or business systems. Whoever gets his or her hands on an unlocked device even briefly has instant access to all information via these apps.

After we removed all sync apps and cloud service apps (that allow access to cloud data or files) from our mobile devices, the risk of losing data to wrong hands significantly decreased. There is very little actual data on our mobile devices and no apps that would provide easy access to data that is stored elsewhere.

Data integrity

Storing important data in multiple locations makes it complex to manage data. How to organize data and files so that the latest versions are available to everyone who needs the information? How do you make sure that backup process really saves all the latest documents and other data when it is scattered around in many places? It can be done, but it is difficult and error-prone.

Storage space

Often, it makes sense to sync more data than you need. You might need that document tomorrow, and all files in that folder, too, and so on. Just in case you need it, you want to sync it. The unfortunate consequence is that every device must have plenty of storage space for the data you believe is important to carry along. It can significantly add to the cost of devices you own.

Having copies of files in multiple locations just in case you need it is a serious security risk. Potentially sensitive, confidential, or valuable data is walking around in a laptop or mobile device that can be lost or stolen.

How to cope without sync?

The simplest solution to organize access to data is to have a central storage of files and data. Users access the data storage with all their devices when they need to. If someone creates or updates a document, it is saved in the central storage. Frequent and possibly encrypted backups are easy to manage.

In practice, this means that a web browser is the key tool for accessing files and for using cloud services - also on mobile devices.

Naturally, there are periods when you simply must have a document, for instance, on your tablet so you can read and work on it on a flight or in a remote cabin on a mountain. Just remember to copy that document on the tablet before internet connection is lost.

A couple of years ago, we moved all our files and shared applications to Nextcloud. It is an open source cloud solution for organizations and individuals who want to self-host their cloud services. Nextcloud is renowned for its options for strong security and privacy.

Owncloud is a similar software package that shares its origins with Nextcloud. Pcloud is a popular commercial alternative for privacy-focused users.

Google, Dropbox, and Microsoft, among others provide free and paid for cloud services. Users have to agree to their privacy and security policies that tend to have privacy risks. An additional risk is losing access to your account because of automated controls that make a mistake (has happened to me).