See
The default encryption key length is 128.
You need to specify encryptionKeyLength=length only if all of the following circumstances apply:
For information about data encryption, see "Configuring database encryption"
in the
The encryptionKeyLength=length attribute can be combined with either
the bootPassword=key attribute or the
The encryptionKeyLength=length attribute may also be combined with the
If you use encryptionKeyLength=length with encryptionKey=key, the key you specify must have the length you specify.