Many users are concerned by the security of address book data. While security is essential to privacy of you and your contacts, it is more practical for you to understand what security level you need, and what resources available for security, while there are many security solutions around.
An SQL database can be secured when authentication mechanism is sound and the database files are kept in a safe place. If the files got stolen, the authentication mechanism will be lost. While it is not rare to encrypt data in a database, however, this will bring penalty to performance, and queries will be made difficult.
Data security is a big topic not likely to be discussed here in detail. Though Open Contacts does not provide built-in security, however, it is easy to use existing resources to introduce certain level of security to Open Contacts.
If you use Open Contacts in LAN environment, you may put the database file in a secured server. Client machines should not be able to access the database file directly, but through Firebird database server. Please work with your system administrator to improve data security. If the contact data contain linked files, the directories of these files should allow client machines to access.
If you use Open Contacts in desktop mode, you has better to run your account in LUA mode, and put the database files into a folder exclusively accessed by your account.
If you use Open Contacts in an external drive, you many consider to use an open source freeware program called TrueCrypt located at www.truecrypt.org. TrueCrypt also support green installation on an external drive. You may then put Open Contacts and related files to the encrypted storage managed by TrueCrypt. Please study the TrueCrypt website for more details.
Please note, we do not provide technical supports to general questions of Windows, LUA, encryption and TrueCrypt etc.