The problem is they are actual charges.
Nope, Cory and tbf, the BBC don’t report the actual charges very clearly. Looking at the Metropolitan Police’s press release, it would appear that the actual charge here are: membership of a proscribed organisation, terrorist training, preparation for terrorism, directing terrorism and possession of articles for a purpose connected with terrorism, variously offences under the Terrorism Acts 2000 and 2006.
The charge is nothing to do with encryptionm, that’s the alleged offending behaviour.