problem in Handling BouncyCastle

[Battula lakshman]

hi all,
I am little novice in developing the Security application. I am devloping an application in which i was supposed to Encrypt the data in the MIDlet side.
I am getting the fallowing Exception
java.lang.NoClassDefFoundError: java/security/SecureRandom: Cannot create class in system package
at org.bouncycastle.crypto.encodings.PKCS1Encoding.init(+35)
at Cryptor.doEncrypt(+64)
at BouncyTest$CryptCanvas.keyPressed(+45)
at javax.microedition.lcdui.Canvas.callKeyPressed(+19)
at javax.microedition.lcdui.Display$DisplayAccessor.keyEvent(+198)
at javax.microedition.lcdui.Display$DisplayManagerImpl.keyEvent(+11)
at com.sun.midp.lcdui.DefaultEventHandler.keyEvent(+121)
at com.sun.midp.lcdui.AutomatedEventHandler.keyEvent(+210)
at com.sun.midp.lcdui.DefaultEventHandler$QueuedEventHandler.run(+178)
Can anybody please tell me how come to include the SecureRandom in this MIDlet.I am unable to find the solution for this.
Please help me in this...
lakshman

[Battula lakshman]

hi all,
I am using the proguard for obfuscation of the Application.AS obfuscator main goal was to decompile and removing the non using classes and including the classes the MIDlet needed.
As expected , i thought that Java.security.SecureRandom will include into the JAR after Obfuscation.
The Java.security.SecureRandom was available in the BouncyCastle, but it did not do anything instead, after running the application it was again giving the application which was little different from the previous one
java.lang.NoClassDefFoundError: java/security/a: Cannot create class in system package
at org.bouncycastle.crypto.encodings.a.a(+31)
at a.a(+64)
at b.keyPressed(+45)
at javax.microedition.lcdui.Canvas.callKeyPressed(+19)
at javax.microedition.lcdui.Display$DisplayAccessor.keyEvent(+198)
at javax.microedition.lcdui.Display$DisplayManagerImpl.keyEvent(+11)
at com.sun.midp.lcdui.DefaultEventHandler.keyEvent(+121)
at com.sun.midp.lcdui.AutomatedEventHandler.keyEvent(+210)
at com.sun.midp.lcdui.DefaultEventHandler$QueuedEventHandler.run(+178)
can you please tell me which will make the application to Encrypt the data by avoiding the Exception at present i am getting
Please rectify me, if i given any wrong information about obfuscators.
Thanks for your help
lakshman