XML signatur applet - Exception: Cannot find DOM mechanism type

Jeg er igang med at lave en applet hvor det skal være muligt at signere en fil med en xml signatur. Jeg har dog nogle problemer med at få den til at virke.
Når jeg forsøger at lave en ínstans af XMLSignatureFactory med

XMLSignatureFactory fac = XMLSignatureFactory.getInstance("DOM");

får jeg den nedenstående fejl. Jeg har ingen problemer i mit test program. Fejlen opstår kun i applet implementeringen.

Er der nogen der har en idé om hvad det skyldes?


Stack trace af fejlen:

javax.xml.crypto.NoSuchMechanismException: Cannot find DOM mechanism type

    at javax.xml.crypto.dsig.XMLSignatureFactory.findInstance(XMLSignatureFactory.java:190)

    at javax.xml.crypto.dsig.XMLSignatureFactory.getInstance(XMLSignatureFactory.java:171)

    at DigitalSignerApplet.signDocument2(DigitalSignerApplet.java:368)

    at DigitalSignerApplet.signFile(DigitalSignerApplet.java:263)

    at DigitalSignerApplet.signSelectedFile(DigitalSignerApplet.java:136)

    at DigitalSignerApplet.access$000(DigitalSignerApplet.java:82)

    at DigitalSignerApplet$1.actionPerformed(DigitalSignerApplet.java:109)

    at java.awt.Button.processActionEvent(Unknown Source)

    at java.awt.Button.processEvent(Unknown Source)

    at java.awt.Component.dispatchEventImpl(Unknown Source)

    at java.awt.Component.dispatchEvent(Unknown Source)

    at java.awt.EventQueue.dispatchEvent(Unknown Source)

    at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)

    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)

    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

    at java.awt.EventDispatchThread.run(Unknown Source)

Caused by: java.lang.reflect.InvocationTargetException

    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

    at java.lang.reflect.Method.invoke(Unknown Source)

    at javax.xml.crypto.dsig.XMLSignatureFactory.findInstance(XMLSignatureFactory.java:184)

    ... 16 more

Caused by: javax.xml.crypto.dsig.XMLSignatureException: Mechanism type DOM not available

    at javax.xml.crypto.dsig.XMLDSigSecurity.getEngineClassName(XMLDSigSecurity.java:70)

    at javax.xml.crypto.dsig.XMLDSigSecurity.getImpl(XMLDSigSecurity.java:130)

    ... 21 more