Grainne and Diarmuid make their public keys known to each other (KG and KD, respectively). They use the session key KGD. Which of the following options (i) or (ii) provides a valid digital signature for the message M? (i) Grainne Diarmuid: {M}GD, {{h(M), KGD, G, D, . . .}K 1 G }KD (ii) Grainne Diarmuid: {M, h(M)}KGD, {{KGD, G, D, . . .}K 1 G }KD

(b) Grinne and Diarmuid make their public keys known to each other (KG and KD, respectively). They use the session key KGD. Which of the following options (i) or (ii) provides a valid digital signature for the message M ? (i) Grinne Diarmuid: {M}GD,{{h(M),KGD,G,D,}KG1}KD (ii) Grinne Diarmuid: {M,h(M)}KGD,{{KGD,G,D,}KG1}KD [10 Marks]