Transforms in Encryptions

• “Transforms” refer to similar possibilities as in Signature
• But the semantics are different!
  • in signature, they are applied on the data to be signed
  • in encryption, they are applied to the referenced data
    • used to locate the encryption data
    • eg, Cyphers.xml contains several encryptions, take the third:

   <CipherData>

      <CipherReference URI="http://.../Cyphers.xml">

         <Transforms>

            <ds:Transform xmlns:r="…">

               <ds:XPath>self::text()[//r:CypherValue[3]]</ds:XPath>

            </ds:Transform>

            ...

         </Transforms>

     </CipherReference>

   </CipherData>