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Welcome to the next session in our python hacking course that is encrypting with the transposition cipher.

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Now, we have seen Cesar Saiful and we have also seen that it is not more secure or the most secure

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one.

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It doesn't take much of a computer to brute force through all the possible keys.

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The transposition cipher, on the other hand, is more difficult to brute force because the number of

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possible keys depends on the message length.

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Now there are many different types of transposition cipher.

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If you look at it now, those different types basically includes the real fanciful, your Saiful, the

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disruptive transposition cipher.

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Now this particular session will be covering a simple transposition cipher, all the columnar transposition

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cipher.

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OK, so in this particular session we would be covering the topics like creating functions with def

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statements, arguments and parameters, variables in global and the local scoop's.

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What is main function?

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The list data types, similarities in the list and strings list of list coming to argument and assignment

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operators using the joint string matau return values and the written statement.

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And finally, the name variable.

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Now we will first of all look at how the transposition cipher will.

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Now, instead of substituting characters with other characters, the transposition cipher rearranges

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the messages symbols into an order that makes the original message unreadable.

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Now, because each GUI creates a different ordering or permutation of the characters and script analyst

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doesn't know how to rearrange these ciphertext back into the original message.

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Now, some steps for encrypting with the transposition cipher are Faustus count the number of characters

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in a message and the key second is you will draw a roll off a number of boxes equal to the key.

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For example, eight boxes for key of eight or something like that.

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Next is start filling in the boxes from left to right and wrong.

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One character PO box.

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Fourth is when you run out of boxes but still have more characters.

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Add another roll of the boxes next year when you reach the last character shared in the unused boxes

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in the last row and starting from the top left and going down each column, write out characters.

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When you get to the bottom of a column, move to the next column in the right, skip any boxes of any,

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and this will be your ciphertext, which is encrypted.

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Now, just to show you how this basically steps work in practice, we will encrypt the message by manually

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and then we will translate the process into a particular program, not encrypting a message manually.

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Now, before we start writing, the code will first walk out on a simple paper or your will you will

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say, for example, a notepad for doing that.

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Now, instead of a notepad, we will use your Excel, which would be easy for us because we already

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have the column in a format that.

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Now, let us take one particular example, for example.

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So now let us take the text, something like Biton hacking Paul's message.

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Now, over here, we will take, for example, the key as the aid in this case.

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Now, the range of the possible keys for this type of cipher is from two the half of the message.

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Now, what is the message size?

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If you just look at this, one, two, three, four, five, six, seven, eight, nine, 10, 11,

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12, 13, 14, 15, 16, 17, 18, 19, 20, 21 to 23, 24, 25, 26, 27, 28, 29, 30, including

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all the characters.

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So the range of the possible keys would be over your from to fill half of the messages.

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That is still 15.

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So we have used over your digits eight.

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But the longer the message you have, the more keys are possible.

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Now encrypting the entire particular paragraph, you can say using the column in a strong position would

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allow you to use thousands of possible keys.

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OK, now what we'll do is first thing will create an eight boxes in a particular room.

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Now let's take four, five, six, seven, eight, eight, OK?

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We'll just make it in a border type so that, you know, it is easy for us to understand and let us

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increase the size of the boxes.

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Each boxer's.

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Let's remove this that's not required, even this one not required.

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We can decrease this, so now we have three, four, five, six, seven, eight, OK, fine.

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All should be visible enough.

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Properly, let's cut and we pasted here so that even this could be removed.

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So now.

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Let's make this trip and even all these boxes also will make it refixed now after we have done this,

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we have the eight boxes which we have created.

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Now, the second step is to start writing the message you want to encrypt into the boxes, placing one

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character into each box.

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So, for example, now you start writing one, one character,

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not even a space that you have.

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We are indicating over here with the particular symbol.

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So let's insert here a particular symbol.

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Let's unleash some special characters.

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OK, so here we have the symbol.

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Now let's place that symbol over here and again, we will continue for one more has been done.

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Now, this particular rule has ended, so now we want another rule below.

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So let's take this.

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And again.

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Let's make it the same formatting and again, start writing here.

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So we had reached in H, e, c, g, i, n, g and again here, let's cooperate it on the same symbol

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C.

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Now, again, we require another rule below, let's take down and do the same thing nowadays, fool,

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you are s e again.

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We require all space and then M e and the last one we will require.

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S s e g, e and dot.

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So let's take a little less.

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And.

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Let's call it on the floor.

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OK, so after this, let's write down here, so we have written this particular way.

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OK, and last thing that we have is a dot.

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So we have even written that the only space is we have stimulated that with a particular symbol.

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OK, now.

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Just to make it more meaningful, we will increase the.

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Foreign sites.

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OK, so this is all we have basically arranged it now, this store are not used.

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So over here, let us give some different background color just to highlight that we are not using this

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particular two boxes because 88 rows or columns would automatically be created.

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So we have created the last two boxes in the last row as a reminder to ignore them.