Shannon Proof of Vernam's Cipher Unbreakability

Here is the short and far reaching proof that Vernam's 1917 cipher is absolutely unbreakable! The same proof implicates AES, DES, RSA, ECC and all other highly regarded ciphers, proving they are all definitely breakable. This cornerstone proof is of great importance for anyone striving to understand the capabilities and vulnerabilities of modern cryptography. A few minutes of mental focus, and you will understand the nature of cryptography much better than if you read volumes of soft crypto analysis.

[@rustycherkas8229]

The XOR swap algorithm is well known (and, obviously, reversible). It seems that what's needed is truly random generation of key values to encrypt. Tricky is for two parties to 'magically' initialise their random number generators to the same starting point, simultaneously contradicting the term "truly random"... With infinite resources, a 'hacker' could generate all possible decryptions, and then is left to sift through those hoping to find a plausible plaintext... The ciphertext "My aunt lost her shoes" could become "The tanks will roll out Monday" or "Tuna are needed for cold fusion"... (No, I haven't counted letters.) We all encode our thoughts with idiomatic influences (lexicon, grammar, 'jargon', accent, tone register, channel selection), all regulated to include/exclude others... Short of a Vulcan mind-meld, it seems to me that no communication can be made absolutely secure against a determined codebreaker. For example: "Pussy" doesn't mean 'pussy' to over half of American voters when said by someone who runs for president... Go figure...

[@innovationsurvival]

Actually, the Vietnam Ciphers was invented 35 years before he patented it Frank Miller, Sacramento banker and Stanford Director invented it. Nice video, thank you.

[@travisx7935]

I guess this is the clearest explaination of the proof I found on the internet, great job and thank you

[@1997cacao]

Thank you for the video. I hope you do more of these. They really help understanding cryptography.

[@GideonTheTeacher]

+bence hambalkó Thanks for the encouragement, stay tuned!

[@jaronandnat]

i love these videos and will watch every one you put up for now on. thanks for the explanations

[@GideonTheTeacher]

+ihategoogleplus Thanks! R&D is 24/7 occupation, but comments like yours drive me to find time and keep the Crypto Academy growing!

[@Mike-kq5yc]

Would you recommend any books or resources about cryptography proofs? And your explanation is perfect

[@DrCortis]

Excellent video. Would like to ask 11:09 shows the joint probability, not the conditional probability. Should the formula be different?

[@fbmch]

Yes, should be as it is in the whiteboard, knowledge of c doesn't change probability of m.

[@cslife7252]

Powerful, Sir. Nice explanation. I have a question- we can always use brute force, right- trying all binomial combinations for the keys. Isn't it?

[@maheshb6558]

CS Life but the number of keys are exponential order in fact 2 power n. Which is difficult to brute force with being a large number n.

[@hkmamike]

Gideon, your videos are great. Articulate and unpretentious.

[@GideonTheTeacher]

+Mike Leung Makes it worth the effort -- thanks Mike!

[@bothaina0_075]

Thank you so much for this video. After multiple hours of research yours was the one that finally helped me understand. Deeply appreciated.

[@GideonTheTeacher]

Thanks. Indeed when I search for information on the Internet I have to discard so many confusing explanations, often not finding a clear and concise one.

[@RaghavSharma-hb1ei]

I was looking for something accurate on this topic and you saved me here. Really Appreciate this Thanks

[@suranjandaw241]

Thanks for the video sir. Great lecture.

[@Keepkip]

I guess you should get a better camera for videos, why only 480p quality

[@GideonTheTeacher]

The camera is OK. I had to set it myself for this video, and didn't do it right.

[@goblin003]

How is this different than a one time pad?

[@GideonTheTeacher]

This is Shannon proof (25 years later) that Vernam's One Time Pad is unconditionally secure.

[@maomxesoax2471]

Something I'm working on. A creates a randomly scrambled char set. Then creates an otp from that set. A sends that otp to B. B creates a randomly scrambled char set. Then creates an otp from that set. B sends that otp to A. Now A sends msgs to B using B's otp and B sends msgs to A using A's otp. The scrambled sets remain private :-) MITM attacks hmmm!

[@Andrei-ds8qv]

Thank you very much, very clear

[@slaozeren8742]

thank you sir!