Great explanation and presentation skills! However, on minute 4.54 you explain why the OTP is unbreakable, but that's actually not the reason that One Time Pads are secure. The reason is that, even if you try ALL the possible keys, you still have no idea which key is actually the right one. So, even if you "found" the corresponding plain text, you won't know which one it is, so a brute force attack is useless.
If you wanna be really cheeky, you can make the 1st 2 Bits and the Last 2 Bits of the entire message map to a "Daily" Word! Then One Time Pad all of it in between then chuck either The 1st 2 to the very end or the Last 2 to the beginning, then if it is divisible by example 3 or 4 or 5 then divide the entire encrypted message by that and do a Transposition cipher and join it all back up again xD. Just use a computer program to handle it and it will be fine sure it's an extra step or 2 but it's worth the data to be slightly more secure than what it currently is, if no Transposition then at very minimum Vigenère Cipher it xD. :)
I did not understand the disadvantages part, specifically that of discovering the key. I imagine the problem is discovering the original message, as we encrypt it to make sure that even if they intercept they cannot read. So why is the problem finding the key, we can already create others, so I see no problem. (sorry if there are errors I used google translator).
Let's say I intercepted some communications between you and some other party. I then have the ciphertext. If I then somehow get hold of the plain text (perhaps I somehow stole it from the other party) I can easily derive the key. If you don't know that I obtained the key and keep using it, I can now read all the traffic. Or what if I saved up loads of ciphertext for months, and then when I finally get the key decrypt it all in one go?
