1. Grid, Web services and Taverna Machiel Jansen Richard Holland

2. The Problem Requirement: Build a WebService which submits job on the Grid pretty easily It must be user and programmer friendly. Do it for a java programmer Adapt Taverna in such a way that it can use a Web Service which uses the Grid. It must be user friendly

3. Problem: Grid authentication On the Life Science Grid every user needs a grid certificate (X509). The certificate functions as a passport. In order to use resources (possibly) all around the world your delegate your credentials for a limited amount of time to the Grid middleware. During that time the Grid middleware can work on your behalf. This is called a proxy certificate.

4. Problem with webservices and Grid Your Grid certificate consists of two files: A public and private part. If a web service wants to submit jobs to the Grid it needs a user certificate. You cannot send the Web Service your credentials. Instead you have to delegate them. This is done by public and private key cryptography. This is needed to make things safe. Then how you do delegate your credentials to the Web Service?

5. Solution: MyProxy MyProxy is an applications which stores credentials and deals out short lived proxy certificates. You delegate your certificate to the store and lock it with username and password. You can send around this username/password combination to the WebService The WebService then contacts the MyProxy server and gets a proxy server with your username and password. The WebService will now submit jobs on your behalf to the Grid.

6. The scenario Client Web Service MyProxy WMS Username password Proxy certificate