bool Sqlite::IsFileEncrypted(const char *DBfilename) {
    FileIn in(DBfilename);

    if (!in) {
        return false;
    }

    String SqlVersion = "SQLite format 3";
    int SqlVersionLength = SqlVersion.GetCount();
    in.Seek(0);
    String version = in.Get(SqlVersionLength);
    in.Close();

    return (!version.IsEqual(SqlVersion));
}

...
        int errCode = sqlite3db.GetErrorCode();
        String errMsg = Format("[ %s&&Error: %d (%s)]", t_("Loading the database has failed!"), errCode, sqlite3db.GetErrorCodeString());
        if (SQLITE_NOTADB == errCode) {
            errMsg = t_("The database is encrypted but decryption failed!&[= Did you use the correct password?");
        }
        ErrorOK(errMsg);
...