I can't decrypt a text encrypted(useing RSA) with publickey on mobile

hi all, I got some problem with my code,

when I wanna use the JSR177 of J2ME to do something about Decryption

here is some of my code as following:

KeyFactory kf = KeyFactory.getInstance("RSA");

byte[] publickeyEncode

x509EncodedKeySpec keyspec =new X509EncodedKeySpec(publickeyEncode)

PublicKey pubkey = kf.generatePublic(Keyspec)

as using that, we can renew our publickey which is from the server.

but there are Exception when I use the publickey to do decryption.

java.security.InvalidKeyException

at com.sun.satsa.crypto.RSACipher.init(+31)

at javax.crypto.Cipher.init(+30)

at javax.crypto.Cipher.init(+7)

at KEYback.startApp(+210)

at javax.microedition.midlet.MIDletProxy.startApp(+7)

at com.sun.midp.midlet.Scheduler.schedule(+270)

at com.sun.midp.main.Main.runLocalClass(+28)

at com.sun.midp.main.Main.main(+116)

however, the problem is solved when I change the DECRYPTO_MODE into ENCRYPTO_MODE

so, is it impossible to do decryption with publickey on the mobile?

[1202 byte] By [JK_taiwana] at [2007-10-3 11:33:09]