keys) is the following 5-tuple: Compound„,, = (pk;;;;, sk;;;,pkasi;, s eig k sk:`,11) (2) Protocol 1 Generating a compound identity procedure COMPOUNDIDENTITY0t, 2: u and s form a secure channel 3: u executes: 4: {pk,";;,skauip 4— guy() 5: 6: 7: 8: 9: 10: uif g ske , e„ c() it shares sku,t,p