We’re rewarding the question askers & reputations are being recalculated! Read more.

# Tag Info

Yes, It is what you understood. You use the same key for each encryption. If you think that they used different keys for each TDES (3DES) they need to store one million keys. This is not practical for the attacker but also for them. It can also be written as $c = \operatorname{TDES}^{(1000000)}_k(m)$ The point in the section distinguishing these iterated ...