I tried to follow the links under "Support for SQL encryption" and ended up in sites where folks talk a lot about C++, .net and Java (JDBC) environments, but it remains unclear (to me) whether current, stable and documented interfaces exist for FPC under Windows and Linux.
Please read again what is written there:
In recent FPC versions (implemented March 2012), SQLDB included support for some extended versions of SQLite3 which encrypt the SQLite database file using the AES algorithm. Use the password property to set the encryption key.
This means that since at least FPC 3.0.0 (which was released after 2012) the
TSQLite3Connection supports SQLite3 libraries with encryption enabled by using the
Password property (*).
For the links below that it's important to read the remarks next to the links to understand what the author is getting at:
Examples:
SQLCipher: open source, e.g. Windows binaries not for free (you have to compile them yourself)
System.Data.SQLite: open source, Windows (32, 64, CE) binaries available, download e.g one of the Precompiled Binaries and rename SQLite.Interop.dll to sqlite3.dll (if you're using the Statically Linked ones, presumably you need to rename System.Data.SQLite.DLL to sqlite3.dll)
wxSQLite3: open source, some binaries for Linux available (ex: https://launchpad.net/ubuntu/oneiric/+package/libwxsqlite3-2.8-0)
The point this is trying to make is that you need a variant of the SQLite library that has encryption enabled which the default library does not have and these links provide potential sources for such libraries.
This can of course be phrased better, but that's what is meant by this. (And using a suitable SQLite library binary is necessary for any programming environment you may use)
(*) Though depending on what you use it might also be necessary to enable the encryption separately as written
here at the point
5.0 C interface where you need to invoke
sqlite3_activate_see() with your product key before accessing an encrypted database.