Blackphone / Android:
In an active conversation, tap on the attachment icon and select an option from the 'Share securely' menu. The options available and appearance of this menu varies depending on your device, below is an example of how this process looks when using a Blackphone 2:
1. Access the 'Share securely' menu and select an app to access the files stored on your device.
2. For example, you can use the 'Documents' option to locate the file you want to share.
3.Tap on the file to send it to your messaging partner.
You need to locate the file you want to share first. This might be in the form of an email attachment, a file stored on a cloud storage service, etc. Once you have located the file, tap and hold it to access the attachment menu and select ‘Open in Silent Phone’. Highlight the contact you wish to send the document to and press the ‘send’ icon. The document will then upload, encrypt and transmit.