Using a 2x2 grid, encrypt a 16-character message of your choosing. Pass it to your partner. (You’ll need four blocks.)
My ciphertext for this question is "IOLVEOCMPTUERCSI".
Click the button below to reveal my plaintext.
Enter your ciphertext below and I'll try to solve it.
Task 3/4
Using a 4x4 grid, encrypt a different 16-character message of your choosing. Pass it to your partner. (You’ll only need one block.)
My ciphertext for this question is "DMYCOEOOCNUDUTRE".
Click the button below to reveal my plaintext.
Enter your ciphertext below and I'll try to solve it.
Task 5/6
Using a 1x1 grid, encrypt the message “cafe”. Pass it to your partner. (You’ll need four blocks.)
My ciphertext for this question is "CAFE".
Click the button below to reveal my plaintext.
Enter your ciphertext below and I'll try to solve it.
Task 7
Take a moment to write down what you have learned in canvas.
Part 2 (Padding)
Task 1/2
Using a block size of 4 (2x2 grid), write the message “A” into the grid and pad it as required. Pass it to your partner.
My padded text for this question is "AXYY". Is this also what you got?
Enter your padded text below and I'll try to unpad it.
Did I get it right? I should have ended up with just "A"...
Did you also get that?
We added one X and as many Y's as needed to finish filling the block.
Task 3/4
Using a block size of 4 (2x2 grid), write the message “XYY” into the grid and pad it as required. Pass it to your partner.
My padded text for this question is "XXYY". Is this also what you got?
Enter your padded text below and I'll try to unpad it.
Did I get it right? I should have ended up with just "X"...
We added one X and as many Y's as needed to finish filling the block.
We did this even though there was already a single "X" because that's our message-- we want it to be preserved.
Keep in mind that when un-padding text we just find the last instance of an X followed by n Y's and remove it.
Task 5/6
Using a block size of 4 (2x2 grid), write the message “1234” into the grid and pad it as required. Pass it to your partner. (Hint: you’ll need two blocks!)
My ciphertext for this question is "1234XYYY". Is this also what you got?
Enter your padded text below and I'll try to unpad it.
Did I get it right? I should have ended up with just "1234"...
We added one X and as many Y's as needed to finish filling the block.
Because we already had a full block, we had to add another full block for padding.
It was important that we do this because we need a way to verify that we unpadded it correctly.
If we hadn't done this, it would be impossible to tell if the message was even padded in the first place!
Task 7/8
Using a block size of 16 (4x4 grid), write the message “A” into the grid and pad it as required. Pass it to your partner.
My ciphertext for this question is "AXYYYYYYYYYYYYYYY". Is this also what you got?
Enter your padded text below and I'll try to unpad it.
Did I get it right? I should have ended up with just "A"...
We added one X and as many Y's as needed to finish filling the block.
In this case, that meant adding a LOT of Y's to fill the remaining 14 spaces.
Task 9
Take a moment to write down what you have learned in canvas.
Part 3 (Product ciphers)
No partner-to-partner interaction is needed for this section of the lab. If you have questions, please see the TA / Professor.
This Instant-Lab-Partner (ILP) entry was authored by Brendan Rood on 10/09/23.