How to transmit information safely
Channels, procedure and common sense in transmitting sensitive materials
Updated 2 August 2026 · 6 min read
A sensitive matter begins with sensitive correspondence. The paradox is that clients concerned about leaks often send passports, statements and descriptions of the conflict in the very first message over an open messenger. Safe transmission of information is not a matter of exotic technology but of correct procedure: minimal data at the outset, verification of the task, an agreed channel, staged transmission.
The guide describes this procedure as practiced by BLACKFILE: what is appropriate to write on first contact, which materials should never be sent to anyone, how a secure channel is agreed, and why the method of transmitting each type of document is discussed separately. It examines common mistakes - from forwarding "the whole folder at once" to discussing the matter with random consultants.
This material is practical in nature and does not replace individual security recommendations for a specific situation.
Who this material is for
- to anyone preparing a first approach
- to clients with confidential corporate matters
- to parties to conflicts at risk of surveillance
- to lawyers transmitting their principals' materials
Questions covered in this guide
- what to write and what not to write in the first message
- how the channel for sensitive materials is chosen
- why documents are transmitted in stages
- how BLACKFILE limits access to materials
- what to do if you suspect that correspondence has been compromised
Contents
- the minimum at the outset: the first-message principle
- catalogue of channels and their appropriateness
- phased transfer of documents
- access scope within BLACKFILE
- signs of compromise and course of action
- relation to the confidentiality policy
specific technologies and channels are agreed individually. Their composition is not disclosed publicly.
Related practice areas
Already facing a similar matter?
Outline the situation in general terms, without documents or personal data. BLACKFILE will assess whether the work can lawfully proceed and propose an approach.