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(male narrator) So now let's decrypt, uh... a message that was encoded
using row-and-column transposition cipher
with this keyword.
Now, this keyword tells me
that there was six characters per row,
and since there are a total of 24 characters in the message,
that tells me that there are going
to be four rows to fill out here.
So I'm gonna have, uh...and I'm just gonna sort of make
a little grid here for my reference.
So we have one, two, three, four, five...
one, two, three, four, five, six columns,
uh...and four rows in each.
Now, remember, the keyword took, uh...tells us the order
in which the columns were read.
Uh...in this case, a, b, c, d, e, f, g, h, i,
j, k, l, m, n, o, p, q, r, s, t, v, uh..to the end.
Okay, so it tells us that they...the, um...columns
were recorded or read out in this order,
and so that is the same order
in which we're gonna need to write them down.
So the beginning of the message came from the last column,
because that would have been the first one to get read.
So we'll write down R, H, A, V in that column.
So then the next four letters are gonna go in the next column:
T, N, U, S.
And then, we're gonna jump to the middle...this column...
the third column here for the next four letters:
that's R, E, D, E.
And then, we're gonna go to the first column.
Remember, this is the fourth one being read.
And so, now we're gonna jot down A, I, E, R.
Jot down the next four characters...
the next four characters are going to be
from the fifth column that was read,
in which case, it's the second column of the original.
So that'd be I, K, A, T.
Uh...and then, the last four characters
will go in the last row, so that's S, O, Q, R.
And let's see what we've got.
So again, now we just read our message out.
So we got air, strike... so we got air, strike...
on...H-E-A-D...head...quarters,
and then an extra character on the end,
which was probably our padding.
So airstrike on headquarters is our decrypted message.