ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with local SQL databases in AIR
Using encryption with SQL databases
Adobe AIR 1.5 and later
All Adobe AIR applications share the same local database engine. Consequently, any AIR application can connect to,
read from, and write to an unencrypted database file. Starting with Adobe AIR 1.5, AIR includes the capability of
creating and connecting to encrypted database files. When you use an encrypted database, in order to connect to the
database an application must provide the correct encryption key. If the incorrect encryption key (or no key) is
provided, the application is not able to connect to the database. Consequently, the application can’t read data from the
database or write to or change data in the database.
To use an encrypted database, you must create the database as an encrypted database. With an existing encrypted
database, you can open a connection to the database. You can also change the encryption key of an encrypted database.
Other than creating and connecting to encrypted databases, the techniques for working with an encrypted database
are the same as for working with an unencrypted one. In particular, executing SQL statements is the same regardless
of whether a database is encrypted or not.
Uses for an encrypted database
Adobe AIR 1.5 and later
Encryption is useful any time you want to restrict access to the information stored in a database. The database
encryption functionality of Adobe AIR can be used for several purposes. The following are some examples of cases
where you would want to use an encrypted database:
A read-only cache of private application data downloaded from a server
A local application store for private data that is synchronized with a server (data is sent to and loaded from the
server)
Encrypted files used as the file format for documents created and edited by the application. The files could be
private to one user, or could be designed to be shared among all users of the application.
Any other use of a local data store, such as the ones described in “Uses for local SQL databases” on page 713, where
the data must be kept private from people who have access to the machine or the database files.
Understanding the reason why you want to use an encrypted database helps you decide how to architect your
application. In particular, it can affect how your application creates, obtains, and stores the encryption key for the
database. For more information about these considerations, see “Considerations for using encryption with a database”
on page 761.
Other than an encrypted database, an alternative mechanism for keeping sensitive data private is the encrypted local
store. With the encrypted local store, you store a single ByteArray value using a String key. Only the AIR application
that stores the value can access it, and only on the computer on which it is stored. With the encrypted local store, it
isn’t necessary to create your own encryption key. For these reasons, the encrypted local store is most suitable for easily
storing a single value or set of values that can easily be encoded in a ByteArray. An encrypted database is most suitable
for larger data sets where structured data storage and querying are desirable. For more information about using the
encrypted local store, see “Encrypted local storage” on page 709.
Last updated 6/6/2012
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