0:00:00.000,0:00:02.000
The only one that is necessary is the second one--

0:00:02.000,0:00:04.000
if the attacker doesn't know anything about the key.

0:00:04.000,0:00:07.000
A one-time pad is a perfect cipher, and as a perfect cipher,

0:00:07.000,0:00:10.000
the computation power of the adversary is irrelevant.

0:00:10.000,0:00:12.000
The first one is not true.

0:00:12.000,0:00:15.000
The second statement is true, because if an attacker knows something about the key,

0:00:15.000,0:00:17.000
she or he will know something about the message,

0:00:17.000,0:00:19.000
which would compromise the confidentiality.

0:00:19.000,0:00:22.000
It is not necessary to assume that the attacker cannot modify the message.

0:00:22.000,0:00:25.000
Modifying the message only effects the integrity of the message,

0:00:25.000,9:59:59.000
but that does not effect the confidentiality.