Hey guys, i just installed ubuntu in a Virtual Box, everything is great, but, i cannot sign apks with it. here is the error that comes up.

Exception in thread "main" java.lang.NoClassDefFoundError: javax/crypto/EncryptedPrivateKeyInfo
at com.android.signapk.SignApk.decryptPrivateKey(Sign Apk.java:124)
at com.android.signapk.SignApk.readPrivateKey(SignApk .java:154)
at com.android.signapk.SignApk.main(SignApk.java:436)
Caused by: java.lang.ClassNotFoundException: javax.crypto.EncryptedPrivateKeyInfo
at java.net.URLClassLoader$1.run(URLClassLoader.java: 366)
at java.net.URLClassLoader$1.run(URLClassLoader.java: 355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:4 23)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 56)
... 3 more