TrustCase at a glance

What’s special about the TrustCase app?

TrustCase is a business messenger app that focuses on secure corporate communication. All messages from sender to recipient are end-to-end encrypted. Message contents cannot be read by any intermediate components such as networks and servers. The app’s architecture is designed to avoid generation of unnecessary metadata (metadata are data at a higher level of abstraction in comparison to the ‘real facts’).

TrustCase is an effective and easy way to coordinate team collaboration. Tasks can be quickly created and assigned. The current status of task processing can be tracked in an overview.

With the help of the FACT24 "TrustBroker" functionality, trusted contacts can be passed on quickly and easily to other TrustCase users, colleagues, etc. This is especially helpful with a large number of contacts. For each corporation, a TrustCircle can be created in FACT24 and filled in with corresponding contacts. The TrustBroker guarantees the identities of its contacts. This way, colleagues' TrustCase address books can be quickly and easily enriched with trusted contacts and cooperation can begin immediately.

The TrustBroker feature is available with the FACT24 edition ultimate PLUS.

Contacts in the TrustCase app are classified in different TrustLevels and identified with appropriate icons, allowing users to see at a glance whether a contact is trustworthy. The individual TrustLevels are described in detail in the Contacts section.


Why do I need to enter a profile name and picture?

Tap the 3-line icon at the top left of the screen to open the menu. At the top, you can see how your profile appears to other TrustCase users. The profile is empty at first and simply identifies you with an ID number. To enable your communication partners to recognise you more quickly when messaging and selecting contacts, it is useful to enter your first and last name, and upload a photo.

Note: it is compulsory to have a username in your profile. A photo is not compulsory, but advantageous to have. Please make sure that the information you enter is accurate as amending it afterwards would cause your QR code to change. This means that you would have to scan your contacts again and be re-scanned yourself.

What's the user ID for?

Users register with TrustCase by providing their mobile phone number, and are subsequently assigned a user ID. This is a randomly generated 8-digit alphanumeric ID which enables users to use the TrustCase app anonymously. The ID is non-transferable and cannot be used on multiple devices.

This TrustCase user ID is assigned to a pair of encryption keys comprising of a private key and a public key. The private key is stored on your mobile phone, while the public key is distributed to your contacts via the TrustCase server. When one of your contacts sends you a message, the message is encrypted on that contact’s device using your public key. You are now the only user that can decrypt the message with the matching counterpart – your private key.

What's the QR code for?

The QR code is your ‘passport' within the TrustCase app. It contains your user ID and public key. When your QR code is scanned, the system verifies whether the key assigned to your contact matches the key stored on the server. This process prevents external tampering.
The mutual QR code scan acts as an identity verification, and thus complies with the (highest) TrustLevel of ‘Trusted’. The individual TrustLevels are described in detail in the Contacts section.


Is there a help service for technical problems?

If you have a problem and require assistance, please contact us at: The emails will automatically be added to our ticket system and will be answered as soon as possible. Normally emails will be answered within hours on working days, maximum 24 hours. You can already find many answers to questions here in our detailed FAQ section.

What's the 'PIN Protection' feature for?

PIN protection in the TrustCase app is a guarantee of enhanced security. If you are working with TrustCase and need to interrupt the process, the PIN protection ensures nobody can access your data (if, say, you do not have PIN protection on your mobile phone or the screen lock has not had time to activate). Ten incorrect attempts to enter the PIN will delete the entire app data.
To activate PIN Protection, go to Settings.

How can I change the font size?

For Android devices: in the TrustCase app go to Menu > Settings > Chat Settings > Font Size.

For Apple devices: go to the phone Settings > Display & Brightness > Text Size > use the slider adjust to desired size. With iOS TrustCase is configured so that changes made in the device settings will affect TrustCase also.

What is 'Web Login'?

Web Login, which can be found under Settings, is for FACT24 users and is a login for the crisis management tool ‘FACT24 ultimate PLUS’.

Symbols and Icons

What do the icons below the input field mean?

By tapping on the “+” in Android, or the paperclip in iOS, to the left of the input field, you summon a row of icons below it.

The camera icon will open the device camera with which you can take photos or videos (iOS) and instantly send to your contacts. With Android: Tap on the video icon to create and send a video file.

The (media) gallery icon opens the device gallery from which you can select photos you wish to send. The maximum file size is 10MB.

If you tap on the microphone icon you can record voice messages. In Android you can find this icon on the right side of the message field.

The task icon allows you to create and delegate tasks. You select a receiver of the task, enter the task description and set response options.

With tapping on the location icon you can send your own location.

Icons TrustCase iOS

Icons TrustCase Android

In Android you can tap on the documents icon to send for example PDF’s and other files.

What are the orange dots shown at the top left of the screen?

An orange dot is a signal that you have received something new. An orange dot on the left indicates a new room and/or message. Tap the Back button to return to the Home screen and look at the rooms icon. A new room is identified by orange brackets. Any new and unread messages are additionally identified by a number after the room.

An orange dot at the top right next to the three dots indicates you have a new task or unread file under Media.

The significance and icons of the individual TrustLevels are explained in the Contacts section.


How do I create a chat room?

Before you can open a room, the TrustCase app must contain contacts who also use the app. The Contacts list shows which of your address-book contacts also uses the app. If your Contacts list does not yet contain any contacts, tap the + symbol to scan in the QR code of a colleague or friend and add them to your contact list (note that your new contact must already have installed the TrustCase app). When scanning is complete, the scanned contact is shown under Contacts as ‘Trusted’ (indicated by the shield and check icon).

How do I add a person to this room?

If you have created the room and are thus the administrator, you can add names to the room you have created. To do this, open the room and go to the menu at the top right of the screen (the 3-dot icon). Tap Room Infos. Now use the + button to add more names to the room.

I've left a room by mistake, how can I get back in?

In order to gain access to a room you must contact the room administrator and ask them to add you back in.  Once a member again, you will be able to see all past content, download files, and continue messaging. When you leave a room, the room name will appear in grey. By tapping on it, you will be able to see past activity, room info, and sent file, but won't be able to write messages or download files.

Note: if you are the administrator of the room which you would like to leave, then upon leaving you must select a new administrator(s) to take your place.

How do I delete a room?

Before you can delete a room you must close or leave the room (‘close room’ or ‘leave room’). A room can only be closed by its administrator, i.e. the user who opened the room.

As a member of a room, you can leave the room and then delete it. First, go into the room. Tap the menu icon at the top right of the screen (the 3-dot icon), then tap ‘leave room’. Then tap the arrow at top left to return to the Home screen. The room is now shown as greyed out. In iOS, swipe from right to left and then tap ‘delete’. In Android, keep your finger on the group until the Trash icon appears.

What is the maximum number of participants in a room?

With TrustCase the amount of room participants depends on the length of the room name and the amount of administrators. Up to 120 participants can be in one room it it has a standard length name and few administrators. Huge rooms with many participants means also a lot of information to be encrypted. Depending on the phone and connection, the process could get a a bit slow.


Various symbols are displayed next to my contacts. What do they mean?

TrustCase focuses on security. Contacts are classified in three different TrustLevels:

tickicon2 Trusted contacts are verified contacts. The QR code of these contacts has been scanned.

personicon3 Matched indicates a match with a contacts that is listed with a telephone number in your device.

qmarkicon2 An Unknown icon flags that the contact is unknown to you. A TrustCase user has invited this contact to join a group of which you are a member (photo or standard image and name are shown faded. A question-mark shows that this person is not known to you.)

The icons in the TrustCase contact list enable you to see at a glance who is classified as trustworthy. The TrustLevel is also explained in the details of each contact. For example, if you tap the word 'Matched', a short pop-up description of the TrustLevel opens. Tap the explanation to close the pop-up. The TrustLevel of a user can always be directly identified in every view of that user.

In combination with the feature „FACT24 TrustBroker“ there is another icon for the visualisation of trusted contacts.

TBicon2 If a TrustBroker shares his contacts out of FACT24 with other TrustCase user, colleagues, etc. via the TrustCircle, these contacts will appear afterwards with the „TrustBroker“ icon in the TrustCase address book of the recipient. For questions regarding the TrustBroker features, please see the FAQ section below named TrustBroker.

Some of my phonebook contacts have not yet signed up to the TrustCase app. What’s the easiest way for me to tell them about the app download?

Some names are duplicated in my contact list. Why is that?

A name may appear twice in your TrustCase contact list if the person has two mobile phone numbers and has registered both of them in TrustCase. To distinguish between the entries, change the entries in your smartphone’s phone book.

In your Contact list, tap the + symbol, then tap ‘Invite persons to TrustCase‘ to send a text message or email with a standard text and download links to your contacts.

Some of my address book contacts don’t show up in my TrustCase contact list. Why does this happen?

As soon as you open the TrustCase app or perform a manual update (by swiping the contact list from top to bottom), the app runs a check of contacts from your smartphone’s phonebook to identify which of them have installed the TrustCase app. When you confirm them, these contacts will be listed in the TrustCase app under Contacts.


How can I send a message?

First open a room by tapping the + symbol. Then select the person(s) you want as member(s) of the room. Give the room a name. You can also select a different room symbol than the default symbol by tapping the icon. Now enter your message and send it.

iOS offers you the option of dictating your message before sending. Tap the message field to open the keyboard. The microphone icon is in the bottom line of the keyboard. Tap the icon and dictate your message. The text appears in the message field. Now simply tap ‘send’ to send your message.

If the keyboard does not show the microphone icon, proceed as follows: Go to Settings, -> General and then Keyboard. Now tap ‘Activate dictation function’.

Is there a limit to the amount of characters that can be sent in a message?

The limit on the amount of character depends on various factors, such as the number of room participants, the message type, etc. During the implementation process we kept in mind that long messages should be able to be transmitted comfortably. By our account, between 1.5 and 5 million characters per message should be possible.

How can I send a document?

In Android you can upload documents from DropBox, OneDrive, etc. into the TrustCase app. Therefore, tap on the orange paper clip which appears below the input field to attach a document.

Alternatively, you can open a document (e.g. pdf, Excel, etc.) in your mail account and tap on the icon to forward it with TrustCase. Afterwards, tap on the desired room and the document will be uploaded automatically and will be marked accessible to all other room participants.

In iOS you can also open a document and forward it into a desired TrustCase room. It is currently not possible to upload documents from iCloud Drive.

Note: You must have, for example, a PDF reader or Excel app etc. installed on your device in order to open received documents.

How can I send a photo?

In Android and iOS you can send photos directly from your gallery. Simply select the photo you would like to send and tap share and then select TrustCase. Once in the app choose the desired room you wish to send the photo in.

Alternatively, you can go to the desired room, click the “+” (Android) or paperclip (iOS) and select the photo icon below the input field, which will take you to your gallery. Similarly, by selecting the camera icon you can directly take a photo and send it straight away.

How can I send audio/voice files?

The following explains how to record and send voice messages on Android and iOS:


  • Go to the room where you like to send a voice message.
  • Tap the orange paperclip at the bottom of the text entry box.
  • Then select the "Microphone" icon. 
  • Now you can record a message and check it afterwards.
  • When you are satisfied with the recording, press "send".
  • Otherwise, throw the message in the trash and pick up a new one.


  • Open the TrustCase room into which the voice file should be posted.
  • Tap on the “microphone”-icon on the right side of the message field.
  • Now you can record your voice message and check it afterwards.
  • When you are satisfied with the recording, press "send".
  • Otherwise, throw the message in the trash and pick up a new one.

What is a “push notification”?

Push notifications let you know of a new message or activity. Usually the app icon and message appear in your notification bar, whilst you are not actively using your application.

Does the app have to be open the whole time in order to receive push notifications?

No, the app will run in the background and users will receive notifications in their notifications bar or lock screen. Make sure that push notifications are enabled.

In order to do this go to your device Settings > More > Application Manager > TrustCase and check that “show notifications” is enabled.

For more information please see the below “I’m receiving delayed push notifications or not receiving any at all. Why is this?”

What happens if I don’t have WLAN or internet access?

If you do not have internet connectivity or WLAN then you will not be able to send or receive messages via TrustCase. Nevertheless, you will still be able to go onto the app and see rooms and contacts. In the case that you are a TrustBroker other TrustCase users will see you as ‘inactive’. This state will remain until you are connected to the internet again.

I’m receiving delayed push notifications or not receiving any at all. Why is this?

TrustCase uses Google Cloud Messaging (GCM) to alert you when a new message arrives. By using GCM the app does not stay constantly connected to the TrustCase server in the background which minimises battery consumption. After 60 seconds of background running the connection to the TrustCase server is discontinued; therefore GCM is used to notify the app when a new message is received.

– Do not ‘Force stop’ TrustCase with the App Manager; this will stop all notifications until the app is reopened.

– Go to your device Settings > More > Application Manager > TrustCase and check that “show notifications” is enabled.

For iOS, please follow the steps below to troubleshoot problems with push notifications:

  • Go to iPhone Settings > Notifications > TrustCase. Check that the badges, sounds and banners are turned on.
  • Ensure that iMessage is enabled (iPhone settings > Messages).
  • Switch your phone off completely. Then switch it on again.
  • Start TrustCase so that it can reconfigure the server push notifications.

Ensure that you are not connected to a wireless network that is blocking the ports which Apple Push Notification uses (try “WLAN off” to see if the push notifications then function).

Regardless of Apple Push you can manually update TrustCase at any time (“Pull to refresh”) on the home screen to check for messages. TrustCase’s messaging function does not rely on Apple Push.


For Android, if the above steps do not solve the issue, follow the procedure below:

  • Make sure you are using the most recent version of Google Play Service and update if needed.
  • Go to Android Settings > Data Usage, press the menu button and check that “Restrict background data” is disabled. In the ‘Data Usage’ menu, scroll to find the TrustCase app and also make sure that the “restrict background data” option is disabled in the settings. Do this for Google Play Service as well.
  • Note: menu options may differ due to Android versions.
  • Temporarily deactivate any system tools like Battery-saver, Antivirus, Juice Defender, xPrivacy, PrivacyGuard or similar, or make sure they are not interfering with TrustCase.
  • Turn off your device’s battery saver mode.

Regardless of Google Cloud Messaging you can manually update TrustCase at any time (“Pull to refresh”) on the home screen to check for messages. TrustCase’s messaging function does not rely on GCM.

Note: a delay of a few minutes may occur on Android 6.0 or later if your device has been inactive for a certain period of time. This is due to the new Doze Mode feature, which reduces battery consumption whilst on standby.

How fast is data transmitted?

TrustCase uses Push Notifications in order to notify your devise of an incoming message. This means that messages should be received immediately. On your smartphone screen the app icon appears and the information “you have a new message”. For security reasons no content details are displayed.

If the app is in active mode, the transmission of pushes depends on your own data connection. From the next iOS release on we’ll have an additional web socket connection, in Android we already have one. The web socket connection offers an even greater reliability and a faster transmission.

When the app isn’t in use the transmission of push notifications (depending on the device manufacturer) is carried out by Google, respectively Apple, to wake up the app.

For more information, please see “I’m receiving delayed push notifications or not receiving any at all. Why is this?”  below.

Creating tasks

How do I create a task?

When you have opened a room with one or more participants (see Rooms), you can create a ‘task’. To do this, tap the three dots at the top right of the screen, then tap Tasks. Tap “+” to create a task. You can now enter the recipient, a description of the task and the reply options. Tap the tick (check box) to send the task.

A task can only be assigned to one recipient. To view the current status of different tasks when you are in the room, tap the three-dot icon at the top right of the screen, then “Tasks”.

Alternatively, you can create a task by tapping on the “+” icon to the left of the input field and then selecting the task creation icon from the options below.

FACT24 TrustBroker ("My TrustBrokers")

Why has the symbol next to some of my contacts changed? What does this mean?

TBicon2 This icon is displayed next to your TrustBroker-provided contacts. It verifies them as ‘Trusted’.

If you would like to know more about what the different icons mean next to your Contacts, please see the Contacts section above and Various symbols are displayed next to my contacts. What do they mean?

What happens if I delete a contact that I received from a TrustBroker but who was also in my Contacts?

Deleting a contact which is TrustBroker provided and in your Contacts will only delete them from your personal contact list. If you delete a contact their profile picture and name will become dimmed and a question mark icon will appear next to them. This is because their TrustLevel will how changed to “Unknown”. They will still remain as one of the contacts which has been provided by your TrustBroker.

Why is it that when I receive contacts from my TrustBroker I have the option to add them as contacts? Are they not contacts already?

The contact which you receive as part of a TrustCircle can be added to your own personal Contact list. In the even that your TrustBroker does no longer wish to be a TrustBroker and cancels their membership, the contacts which you have received from them will remain in your Contacts.

Why do I have more contacts now then the last time I looked at my Contacts list?

Whenever the TrustBroker scans new contacts onto their device, and are scanned in return, the TrustBroker has the option of making those contacts public to their TrustCircle. As you are a part of that TrustCircle you will receive the new contacts which the TrustBroker scans and chooses to share.

Why are there certain users in Rooms with me but they are not in my Contacts?

If the TrustBroker from whom you have acquired your contacts has set any of them to ‘Private’ you will only be able to see them in Rooms you share but not in your Contacts. If the user is set to ‘Public’ then you will be able to see their details in your Contacts also.

Why can I not change my profile after I become a member of a TrustCircle?

After you have scanned the QR code of the FACT24 TrustBroker in the contact data maintenance form, you have become part of a TrustCircle and can make no further changes to your profile data. This is for the following reason: As soon as you are a member of a TrustCircle, the information you provide is considered "Trusted". If you make changes to your data, the new information will no longer match the original information. So if you change your profile details, the trust can no longer be verified. Once the information you provide is used to generate a unique QR Code, changes to the information would also change the QR Code.

For this reason, you should provide your details and your profile picture in the contact data maintenance form, which you receive by mail from FACT24, in such a way that you are satisfied. If you would like to change any part of your profile details at a later time, you must delete the TrustBroker in the TrustCase app, make the changes you want, and rescan the TrustBroker QR Code; You would have to once again sent the contact data maintenance form. Or you can directly ask your responsible FACT24 TrustBroker that you would like to adjust your data and therefore need the contact data maintenance form again.

What do the grey lines next to each TrustBroker mean?

The 3-lined symbol in grey to the right of each name allows you to order the TrustBrokers. The order of the list represents the prioritization of the TrustBrokers for the user. When a new TrustBroker is scanned they will be added to the bottom of the list and hence have the lowest priority. The TrustBroker at the top of the list has the highest priority. This prioritization refers to which TrustBroker, and their TrustCircle contacts, will be refreshed first, second, third, and so on.

Note: with iOS, when on the TrustBroker page, you must first tap on the ‘Edit’ button and then the grey lines next to the TrustBroker will appear.

Data security

How is my information protected with TrustCase?

All messages, including any attached images, documents and tasks*, are end-to-end encrypted from sender to recipient. The interim components such as networks and servers cannot read the message contents. The architecture was designed to prevent generation of unnecessary metadata; this means that only metadata that is relevant for message delivery is tracked.

*Files are encrypted using a randomly generated symmetrical key which is transmitted to other group members in asymmetrical encryption (using xsalsa20/20 and 256-bit key length; see NaCl Open Source Encryption Library at for details).

See Settings -> Licences for an overview of the software used in the TrustCase app.

What data is stored?

The basic principle behind the TrustCase app is to provide a highly secure business messenger service with a range of practical functions. Storing or managing data is not in line with this principle (for more information, see Settings -> Data Protection).

The TrustCase server is used to transmit messages and data. Temporary storage of the data on the servers is necessary during the period required to transmit the message. External interception of data during transmission is futile because all messages and media are end-to-end encrypted and can thus only be decrypted by the recipient with the appropriate key.

No data in plain text format is stored. Telephone numbers are stored in anonymised (hashed) form, while content, profile names and profile images are exclusively stored in encrypted form. The keys are not known to TrustCase.

You manage your contacts yourself on your personal device. When your TrustCase contacts are synchronised with your smartphone’s phone book, this data is transmitted in anonymised form to the TrustCase servers and subsequently deleted.

Each user ID is assigned a pair of keys (private and public key; see Profile “What’s the user ID for?”). The keys are generated locally on individual devices, so that the private keys – the counterparts essential for encryption – are not known to TrustCase.

The user IDs and public keys generated by TrustCase itself are not encrypted as they are used for the actual end-to-end encrypted message exchange.

Where are the servers located?

The TrustCase servers only store data that is essential for message transmission. The servers are located in Frankfurt am Main and are thus governed by German law. The data protection level imposed by the German Data Protection Act (BDSG) is known as one of the most rigorous in the world.

Operating systems / devices

Which software versions are required to download the TrustCase app for iOS or Android from the corresponding store?

The TrustCase app is designed for Android version 4.4 or higher.

You need iOS 10.0 or higher to display the TrustCase app in the app store and to download it.

Which operating systems is the app available for?

TrustCase is currently available for both Android and iOS.

I have a new telephone number. What do I need to do?

When you registered with the TrustCase app, an ID was assigned to your mobile phone number. If you get a new phone number you will need a new ID. You cannot use your new phone number and ID to access your previous data from the old phone number.

How can I backup my data?

You can run a data backup of your chat record and contacts (including TrustLevel) on your new or reset device.

In iOS, you can back up your data to iTunes. The Apple Website provides a detailed step-by-step guide to the procedure.

Note: It is important that you make the backup to your computer (set checkmark at “This computer”) and not at “iCloud”.

Activate “Encrypt iPhone backup” so that specific data (e.g. contacts, rooms, etc.) will also be backed up.

Many Android device manufacturers offer individual backup procedures which can only be run on new devices from the specific manufacturer. In addition, backup apps such as Helium also provide such support.

How can I migrate data to a new device?

To migrate your data from the TrustCase app to a new device, you must first run an encrypted backup (see above).

In iOS you can transfer the last backup of your old device to your new device via iTunes. The procedure is described in detail on Apple’s support page.

You can use Android Backup Service to migrate data to your new device, provided you first back up the data in your Google account. See the Google website for a description of the procedure.

After migrating the data you can continue to work with the TrustCase app as normal.

If you have questions please contact our support team:

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