FAQ & Troubleshooting

New Boxcryptor for iOS version

Why Did You Choose “Files App First”?

With iOS 11, Apple introduced the Files app as the central hub and designated way to work with files on iPhones and iPads in 2021. Besides the default storage locations iCloud and "On my device", apps like Boxcryptor can integrate with the Files app and provide their own files and folders. At the same time, other apps can integrate the Files app in order to seamlessly work with exactly those files.

The Files app is a huge improvement for workflows spanning multiple apps to get your work done. Our mission and promise at Boxcryptor is and has always been to secure your files stored in the cloud.

Our mission is to become the service of choice for everyone who wants to secure files in the cloud. Today, cloud computing is part of our everyday lives and it is continuously changing and evolving. The influence that cloud computing has on our personal and business lives will have a lasting impact on our world. Therefore, data security in the cloud is of highest priority. Personal and sensitive information are valuable property that must be protected – today and always. Boxcryptor was born inspired by our passion for cloud computing security and our wish to find new solutions to make our lives a little easier and more secure. As we grow, we will continue to protect information across devices in the cloud and to develop services and solutions as needs and wants evolve.

This mission is our guideline when developing Boxcryptor now and in the future. Files app first is an important step on this journey and ensures that we continue to meet our customer's requirements in 2021 and beyond. You can learn more about the advantages of the Files app here.

Why Did You Remove Your Own File Browser?

On one hand, developing and maintaining your own files browser including all bells and whistles requires a huge effort, on the other hand it can never match the experience Apple is able to provide with the Files app due to its central and deep integration in iOS and other apps.

Focusing on the Files app integration allows us to provide a more clear user experience by having a single place to work with your encrypted files and also to opimize our development resources around our core value proposition: The best end-to-end encryption solution for cloud storages.

Why Did You Remove the App Protection?

Apple defines how third party apps integrate with the Files app and we can only implement features in the boundaries of the iOS platform. While we would have preferred to keep App Protection, it is technically impossible to provide such a feature in the Files app in a secure way.

We are closely watching the development of the Files app and whether Apple will create the conditions to implement a secure App Protection feature in the future. Until then, iPhones and iPads offer great and secure options to lock down your device and we recommend to make use of passcodes, Touch ID and Face ID if available.

Can I Use Boxcryptor To Hide Some Files, Photos or Videos on My Device?

We're sorry, but this use case will not be achievable with the new Boxcryptor app. While Boxcryptor could be used to hide some files, photos or videos on your device in the past, this was never our goal for developing Boxcryptor and merely worked coincidentially.

Our mission has always been to secure your files in the cloud, not on your device. iPhones, iPads and iOS offer a plethora of security controls to protect your device from unauthorized access, ranging from TouchID and FaceID, T2 chips and the Secure Enclave to local device encryption. You can read more about it at Apple's Website.

If you only want to hide some files, photos, or videos on your device, Boxcryptor is not the right app for you and we recommend to switch to another app which has been developed for this use case. Here are some recommendations how files, photos and videos can be hidden on iPhones or iPads.

But I Don’t Trust Apple, iOS or the Files App

Apple owns the hardware, the operating system, and all core apps running on your iPhone or iPad. It is impossible to develop a third party iPhone or iPad app which can protect data against Apple as an attack vector.

If you do not trust Apple, iOS or the Files app, the only real solution is not to use an Apple device. You should only use devices and operating systems which have your trust.

App security always relies on operating system security and operating system security always relies on hardware security. Thus, trust is inherited: Hardware must be trusted to trust the operating system. The operating system must be trusted to trust an app. If trust for the hardware or operating system are missing, this trust can never be restored by an app.

The new Boxcryptor app is as secure as the old one was. Even if you disabled the Files app integration in the old app, Boxcryptor – just like every app - always used functionality provided by iOS, e.g. to perform the actual encryption and decryption or to preview files within the Boxcryptor app. Files in the Boxcryptor app have always been exposed to Apple's software and hardware - regardless if the Files app integration was used or not.

Just like iOS, the Files app adheres to the highest standards for privacy and data security found in the industry. Other apps can only access files in the Files app if you explicitly opened a file. It is not possible that other apps secretly access your encrypted files in Boxcryptor via the Files app behind your back. You can learn more about the security of Apple platforms here.

But I Don’t Trust Other Apps

By default, the Files app automatically opens a file in another app if it supports the file type. For example, Word documents will automatically open in the Word or Office app if it is installed.

If you have apps installed which you don't trust, the only real solution is to uninstall them. You should only install and use apps which have your trust.

If you do not want that a specific file opens in another app, you can use the Quick Look feature of the Files app to preview a file directly in the Files app. You can learn more about it here.

Can I Just Continue To Use the Old Version?

Unfortunately, the App Store does not offer a way for users to install older versions of an app. Apple only allows to install the latest version of an app available for your device and there's nothing we can do about it.

I Do Not Want To Use the New Boxcryptor App Anymore. Can I Get a Refund?

If the new Boxcryptor app does not meet your requirements anymore and you just cannot continue to use Boxcryptor, we offer a goodwill refund of your remaining subscription on a case by case basis. Please contact us via support@boxcryptor.com to request a refund.

Boxcryptor does not show up in Files app

In some cases, Boxcryptor is not shown directly in the Files app after installation.

To solve this issue, the device must be restarted.

Use self-signed Certificates for Cloud Provider

Connecting to self hosted WebDAV or Owncloud / NextCloud instances with self-signed certificates does not always work out-of-the-box.

For Boxcryptor to connect to your server, you must install your self-signed certificate on your iPhone / iPad. For more information how to install it, please see here.

For more information on certificate requirements, check apple's specification here.

If you own the domain, you can instead create a free and trusted certificate. For more information, see Authorities such as Let's Encrypt.

I Cannot Move a File to an Encrypted Folder

Moving files between encrypted folders or into a new encrypted folder always requires encrypting the files with the new folder key. Hence, Boxcryptor has to download the item, decrypt, encrypt, and upload the item again. This would present an obvious strain on your bandwidth. Since users might no expect this much data usage for a simple move/copy operation, we decided to disable the option to move and copy between encrypted folders.

Where can I download Boxcryptor Classic?

Boxcryptor Classic is the predecessor of Boxcryptor which has been discontinued. It is not recommended to use Boxcryptor Classic because it is not supported anymore and does not work on the latest operating system versions.

If you’re an existing user of Boxcryptor Classic you can download it here and we recommend you to upgrade to Boxcryptor as soon as possible.

Boxcryptor Classic for iOS is not available on in the App Store anymore.

What happens if Boxcryptor goes out of business?

Boxcryptor has been designed in such a way that Boxcryptor continues to work even if the Boxcryptor servers are not available and you're still signed into Boxcryptor. If you want to take additional precautions for the event that the Boxcryptor servers would go permanently offline, you must have the following backups:

  • Exported key file
  • Boxcryptor installer file

When these files are available, you will always be able to access your encrypted files on your own on any supported operating system - without any connection to any server. The exported key file contains all encryption keys associated with your Boxcryptor account. Important: As new keys might be added over time by Boxcryptor's integrated key management (e.g. when sharing files with other Boxcryptor users), it is recommended to regularly export a new key file.

After installing Boxcryptor, you can use the exported key file to access your encrypted files using a local account. Learn more about exporting your keys and local accounts.

Outdated Clients

We regularly release new versions of Boxcryptor with new features, better stability and overall improvements and retire outdated versions over time. On September 30 2018, the following versions have been retired:

  • Boxcryptor for Windows 2.22.706 and older
  • Boxcryptor for macOS 2.19.907 and older

When you try to use a retired version, you will not be able to use Boxcryptor and receive one of the following error messages:

This client is invalid or outdated. Please upgrade to the latest version.

The client id is invalid!

This is no secure connection

The remote certificate is invalid according to the validation procedure

Boxcryptor can't establish a secure connection to the Boxcryptor server.


Download and install the latest version of Boxcryptor from here. Afterwards you will be able to continue to use Boxcryptor.

If you still see the error message This is no secure connection, the problem lies elsewhere. Check out I Cannot Connect to the Boxcryptor Servers.

I am using Windows XP or Mac OS X 10.13 or earlier

Current versions of Boxcryptor require Windows 7 and later or macOS 10.14 and later. As all earlier operating system versions are not supported by Apple or Microsoft anymore, we recommend affected users to update their operating system to a newer version as soon as possible in order to stay safe.

Using unsupported operation systems poses a huge security risk. You really have to update your operating system for security-related use.

I cannot update to the latest version

Note: If you are using Windows, please look into I Cannot Update or Uninstall Boxcryptor first.

If for any reason you cannot update to the latest version and can't access your encrypted files anymore, you have the following options:

Boxcryptor Portable

Boxcryptor Portable does not require any installation and can be used to access and decrypt your encrypted files without administrator rights. Download Boxcryptor Portable here.

Key Export

You can export your keys from our server and use a local account to sign in to your outdated Boxcryptor version without requiring a connection to our servers. Learn more here.

I cannot sign in due to too many connected devices

Sign in to your account at boxcryptor.com and remove a device which is no longer needed. Then try again to sign in.

Cannot open some files

There may be situations where files appear to be inaccessible. This can have multiple reasons:

Boxcryptor Access Issues

On desktop some Applications or the file browser shows a message with Invalid parameter when trying to open a file.

  • Boxcryptor is eventually signed-in to a wrong account. → Check the account info in the Boxcryptor settings and compare it with the Boxcryptor permissions.
  • The user has no Boxcryptor permissions on the file. → Make sure the user has physical access to the shared file, has Boxcryptor permissions correctly set and the latest permission changes of the file have been synced. Learn how to set permissions here.

Filesystem Permissions Issues

Files are read-only or "permission denied" is displayed. Change files system permissions so your user can (physically) access them.

Sync Issues

"Bad padding" issues, empty physical files or inaccessible folders due to an empty Folderkey.bch file.

File open shows "Found invalid data while decoding" and the .bc file is empty.

Folder cannot be opened "Found invalid data while decoding." is displayed in the permission settings.

There has been an incompatibility with Dropbox in the past that could create "broken" content for smaller files because Dropbox did not sync the last file change.

  • restore an older version of the corrupted file via the file history of your cloud storage provider.
  • for folder issues, delete the empty Folderkey.bch file and re-encrypt the folder.

There is a File Called FolderKey.bch in my Cloud Storage. What is This?

Boxcryptor creates a FolderKey.bch file when a folder is encrypted. It contains encryption metadata for its parent folder and helps Boxcryptor to maintain the encryption hierarchy. This file is not visible within the Boxcryptor drive.

Does it Leak Sensitive Information?

The FolderKey.bch does not contain any sensitive information. Only .bc files contain sensitive information — and these are encrypted.

What Happens When I Lose it?

Dont't worry, you will not loose any data or access to files. All crypto-required information is stored directly within your encrypted *.bc files.

The downside of losing that file is that Boxcryptor no longer perceives the parent folder as encrypted. As a consequence, new files in this folder will not inherit the encryption setting.

There is a File Called .bclink in my Cloud Storage. What is This?

The file helps to verify the account when linking accounts to use features like Whisply.

If the file doesn't exist, the user either used a different account for linking or the sync client is not turned on/syncing.

Does it Leak Sensitive Information? Can I delete it?

The file does not contain any sensitive information. It is not necessary and can also be deleted. However, it may be generated again automatically.