The Science of Codes: An Intro to Cryptography

[@scabiniful]

passing notes in class just got a lot more interesting

[@afeishalopez4524]

hahah😂😂😂😂 true

[@Combes_]

@@xingyuliu1890 i bet they won't when they don't get caught passing test anwsers because they used the cipher

[@erlynvasquez1962]

I gave this to a crush I had

[@bitonic589]

hah, ik this is from 8 years ago, but imagine a teacher so confident aboutta bust a student, but then seeing "faojnfb hbba klpp hanv kkso"

[@imnotcool1203]

THAT'S WHY I SEARCHED THIS UP

[@NukeIvex]

When you crack Caesar ciphers, do they ask "Et tu, Brute force?" Hides from impending mob.

[@AplaTaSpaw]

Kevin Xue Oh man exactly my kind of humour...well played :D

[@Leah-xe6xs]

Huh?

[@dominic2446]

i dont get this.

[@SomeBuddy777]

You don't get his story!

[@sureshotshorts1207]

Haha man....!

[@d.tt.wilding7740]

he's telling me this so enthusiastically like if he's helping me get away with a top secret. I almost feel bad for having nothing to hide

[@govindagovindaji4662]

LOL~!

[@ShadowGhost-n8d]

Interesting. Hmmmmm

[@chaz8837]

Enigma is a truly brilliant approach to cryptography. The weakness is the common wording of course. So we can take common words out of the cipher altogether. When using enigma one must not use common words at all. so we can make different substitutes for common words like "the"

[@JamesDavy2009]

Or »das«, »der«, »die« and »Fuehrer« back when they operated them. In fact, Enigma messages began with a three-letter operator code (at first repeated once to make a six-letter operator code).

[@gecsus]

The answer is too simple. Simply group all the words into 5 letter groups and there are no common words to find. It comes out like this "thisi sames saget hatus esfiv elett ergro upsin itfin" It's just not translated for clarity. If you can't read it, it says "this is a message that uses five letter groups in it fin."

[@himesilva]

@@gecsus That somehow seems too obvious. Would it really work?

[@gecsus]

@@himesilva It actually is used by military. When a message is encoded it must be grouped into 5 letter groupings so that the common word sequences are not obtainable. Otherwise it would be easily decoded. Could you even recognize the message example even though it wasn't encoded? The next problem is letter frequencies. Like "E" is the most commonly used letter in the alphabet for English words. Words like it, we, us, be, etc, are limited in number. Single letter words a very easy as well, as they are VERY limited in number (I, & A)

[@TheYafaShow]

Two cryptographers walk into a bar. Nobody else has a clue what they're talking about.

[@ShallowBeThyGames]

***** Who'd have known a cryptographer would be scuppered by predictive text.

[@stuvs830]

@Ka P that took me a sec.

[@TaylorYarick]

+Stu VS I'm not gonna lie. I don't get it

[@цветок-ш7п]

+TheYafaShow lol i got it in less than a minza

[@TaylorYarick]

I get Ka P's joke now. I thought you'd all like to know that. It only took 3 months

[@squee6970]

Brute force is pretty effective on Caesar

[@nicholasdreesen3223]

even a brain could be decrypt caesar xd

[@maron3563]

agree :D

[@maistromann136]

I understood that

[@vanillatwilight82]

I just screamed this is too funny i hate it

[@TheMultipower47]

Too soon

[@MetaBloxer]

"This should look like gibberish to you" *Gestures towards ad*

[@apersonthatisliving5810]

MetaBloxer nope

[@carpenter3461]

lol

[@theoneshad0w508]

How about a crash course series on this? Like if you agree.

[@manguy01]

I learned the Caesar Cipher in 4th grade. My teacher was awesome. _edit: 5th grade._

[@SeaZucchini]

***** For 8 year-olds. That's kinda... I dunno, the point?

[@batman88891]

Matthew DeLeon Most fourth graders would be 9, wouldn't they?

[@GhostKreep]

batman88891 nope

[@AwkwardCheeseIsAwkward]

batman88891 Depends on where you started.

[@QuickLs3ns3]

MicManGuy Wtf SciShow i rewatched numberphiles videos about the enigma machine and then 3 hours later u post this video about Cryptography.. Are u spying on me? Spooky

[@filipepontelima8305]

I work with cryptography and I have to say: this video is amazing. Great way to teach the history of cryptography in a way easy to understand. Also very accurate and covered the most important topics of the history of cryptography

[@lunam7249]

your comment was very clear,...i doubt your a codewriter....hahaha

[@DampeS8N]

Very nice primer on encryption with examples. Great job! I hope you do a part 2.

[@heathermarcoux294]

another giveaway worth mentioning is that in your message "scishow is the greatest" you use a common two letter word, and there's only a handful of two letter words those letters could be which makes it easier to guess the proper match. Also if you had used a single letter word, there's only two possible choices because the only single letter words are "I" and "A" (assuming you're not using txt lingo)

[@Suedocode]

No mention of public/private key encryption (RSA/ECC) or the current symmetric key encryption (AES)? The schemes you provided are technically symmetric key encryption, and it's such an important word/concept that I'm surprised it wasn't specifically pointed out. RSA, ECC, and AES are the most important and relevant encryption schemes. A topic about cryptography is rather silly without them, even if it's only rudimentary stuff. You don't need to describe the math behind it, but mention the concepts at the very least.

[@tipomartins]

Jeremy Joachim I think they will do it in future videos, this was just the first part!

[@RSP13]

Jeremy Joachim It's better to present properly just a few topics then to simply scratch the surface of several ones. I would be pissed if they attempt to explain RSA is 30 seconds.

[@thegingersheep]

Jeremy Joachim While I understand the reasoning behind what you said I have to say I partially disagree. While it is true they could of gone into more advanced/modern encryption methods. This show is primarily intended to provide and introduction to topics. This allows those who are interested to explore additional information and those who are not interested to learn some and then move on.

[@filipepontelima8305]

Jeremy Joachim This video was clearly only about the history of cryptography. It's very complicated to explain all that for everyone and expect it from an 8 minute video is unreasonable. But the concepts introduced in the video were great and all the information absolutely correct. The only thing that the video could have mentioned is the illogical use of the one time pad: "if you have a secure way to send the secret key, why not send the message itself through this comunication, since it has the same size?" But the video was amazing.

[@Suedocode]

+Filipe Ponte Lima "This video was clearly only about the history of cryptography." But it says "The _Science_ of Making and Breaking Codes". This is like titling a video "The Science of Light" and then talking about aether the entire time. "if you have a secure way to send the secret key, why not send the message itself through this comunication, since it has the same size?" You can hand them an enormous one-time pad in person once, and then have secure communications thereafter. It's much more preferable than handing them messages in person every time.

[@laurafleming4377]

You should cover quantum cryptography - it's actually unbreakable

[@NearlyInfinity]

It is to current regular computers but not so much to other quantum computers

[@RevolutionibusOrbiumCoelestium]

Laura Fleming - Actually that’s incorrect. Quantum cryptography is easily breakable with other quantum computers.

[@NearlyInfinity]

@@RevolutionibusOrbiumCoelestium Only as much as current encryption on normal computers is to break on normal computers, but quantum cryptography is un breakable to regular computers which I think they are talking about

[@onyanchamotanya973]

The dai I saw a chain break through a tarmac road I knew everything is breakable

[@Gruggo]

This was an incredibly interesting episode, I ended up spending at least an hour reading about encryption and hashing after watching it. Very, very interesting indeed.

[@Kneedragon1962]

It may be worth mentioning that the 'Bombe' made by Allen Turing and Tommy Flowers, was in many ways the world's first real electronic computer. It predated the American Colossus computer by about 4 years, and inspired it. Subsequently, Von Neuman (who had worked on Colossus) made a set of recommendations, should anyone attempt to build another one of these things. His recommendations led to the building of the first Von Neuman machines. All modern computers could reasonably be described as Von Neuman machines, because 75 years later they still comply almost exactly with Von Neuman's recommendations. Codes, specifically the Enigma, gave birth to modern computers. And, much as the NSA may annoy us, without espionage, there would be no computers.

[@NotronLP]

6:16 There is a movie about that called ''The imitation game''

[@annashklover3023]

That's my favorite movie!

[@Adjuni]

Love that film. Made me really sad how they treated Turing after the war. :(

[@beecomesover]

yeah, watch 2 times and still love it though

[@grantreynolds_1]

Fantastic film

[@fairlylocaldreamer7917]

Yes! One of my favorite movies ever!

[@wow5212]

Tips for simple but effective encryption (can be programmed in python) : 1) Include spaces, commas and dots in your alphabet list as 27, 28 and 29 respectively. 2) Carry out alphabet substitution. Example : a - t, b-k, c-s ...... 3) Then, apply vigenere cipher with long key. Example : "thispasswordissohardnobodywilleverguessit" 4) Don't use capitals. It makes it MUCH easier to crack. Your end text will be completely gibberish with random dots, comma and spaces. There will be no common word lengths such as 3 for "the", 1 for "I" and others.

[@franatrturcech8484]

the problem is that you can only encrypt text, and with a long enough message, even frequency analysis can still be done. there is no diffusion, the mapping is still 1->1

[@Imedge6]

One of the best interesting episode ever !

[@Flashzinh0]

Mat G For sure !

[@stevie-ray2020]

Despite the fact that hours could be spent explaining the cracking of codes, this is an excellent and concise explanation of ciphers and deciphering!

[@resisx07]

Mat G " "Cribs". HA !

[@rich3of3]

Mat G yes, I agree

[@stevenroyalton7789]

Mat G One of the best interesting grammar ever !

[@cheerios428]

This video is great! My girls who code class is doing our Cyber Security/ Cryptography unit this week and this is such a perfect video to show them! Thanks SciShow!!!!

"When websites announce that hackers know everything about you, that's because their encryption methods were breakable" That's not true. Most of the time the website are broken into because of unpatched or misconfigures software. It's extremely rare to be hacked because of a flaw in in the encryption methods.

[@PirateTHESteam1]

Toni Lähdekorpi Well, you are partially right. You see when you hack a website you usually retrive a database filled with information. The information in this database can often be encrypted, so if you want to be able to login to lets say one of the admin accounts, you'll have to decrypt the usernames and passwords first. The method of encryption varies greatly from AES to no encryption(plain text).

[@isaackarjala7916]

PirateTHESteam1 in the case where an encrypted database containing passwords or credit cards is stolen, they advise changing your password and credit card out of an abundance of caution not because they believe that there is a credible risk of cryptanalysis cracking the crypto.

PirateTHESteam1 If they access your servers and database, they will most likely also gain access to the code itself and the keys required for decrypting anything decryptable. Passwords aren't (or shouldn't ever be) ecrypted with anything other than a one way hash that by design can not be decrypted, but rather the password is always rehashed and compared to the stored one on login. But even with the decryptable data, the problem isn't a flaw in the encryption itself.

[@Fenriswaffle]

PirateTHESteam1 So if I encrypt all the passwords with MD5 I'm safe rite? I'm kidding. Though I have to ask, if say for instance you DO have a database where the passwords are encrypted using MD5 for whatever reason, would it be possible to switch to another algorithm and update the password rows accordingly?

***** Yo dawg, you could always hash the easily brute-forceable MD5 hash and then remove the MD5 part on login.

[@Kio_Kurashi]

I've made several cyphers most of which were variations of the basic ones such as Caesar's. Two of which I'm somewhat proud of. The second one is newer and not yet refined but the first one operates as such: You pick a two digit number. In this case we will use 27. Now we write out the alphabet in order in a line. Using the number of letters in the first word of our message as a key we write the 10's digit out as many times as there are letters in the word above the alphabet. Continue in this pattern going up in numbers. So 3, 4, 5... Once you have finished on top we take the one's digit and work are way down. In this case 7, 6, 5, 4... The difference here though is that we are skipping letters equivalent to half of the key rounded up. You still use the number the same amount of times. Using the top number you will create groups of the same number which would give you different numbers on the bottom. If we were to encode "This is easier than expected." then you should have something that looks like this: 2222 3333 4444 5555 6666 7777 88 abcd efgh ijkl mnop qrst uvwx yz 5375 3753 7527 4264 2642 6416 31 We now put the groups in order listing the lower numbered groups from lowest to highest. in this case we get yz qrst efgh mnop abcd uvwx ijkl. Now we take our original number which will become our second key (and a guide for the receiver) and count through all of the letters that number of times.what we land on we then take out and use for our letters in order. I.e: ABCD EFGH IJKL MNOP QRST UVWX YZ ZREM BXSA LCFK IJTP GQOH UWDN VY But there's more! Capitol letters get shifted to the left by a factor of the first key (the letters in the first word). This means that instead of the 'T' in 'This' becoming a 'H' it becomes a 'P.' Fully translated it goes as follows: "This is easier than expected." "Palo lo bzolbq hazj bnpbehbm."

[@shattywack]

Never really gave this subject any thought before. Man, I love this channel

[@kujmous]

I made an encryption process is even more powerful in that it iterated through a polyalphabetic cypher for every character just to regenerate a unique key for the subsequent character. This key regeneration was done for every ASCII character, 1 through 255. Pretty proud of it.

[@GelidGanef]

Crash Course: Cryptography & Cybersecurity? PLLLZZZZZ!!!

[@favian95]

The logic is so simple and yet the execution is so complicated

[@Seraphii874]

It's so weird not seeing youtube views freeze at 301 anymore O_o

[@manurmad1539]

Has it really been 4 years since that was a thing?

[@Needformadness2]

@@manurmad1539 longer actually

[@vyrin]

those were the days

[@crazyd3mon968]

I had trouble understanding the vigenere cipher before watching this it's really helped me to make sense of it thanks. Edit: Just used a vigenere cipher to test my friends hopefully I did it right

[@SittingGuy]

This stuff is way too advanced for me. So I'll just keep sitting on things :D

[@Mazzolli]

Sitting Guy do you babysit?

[@willlegok9]

This is extremely simple.

[@Leitilumo]

What...?

[@perspectivedetective]

***** Ok, I don't know if this will work, but it's the only thing I could find: First, hover your mouse over the user's profile pic. That should bring up the google plus hover-over menu. Click on the little 'g+' logo to go to their google plus profile. Once there, look for the little down arrow below their profile pic/circles info on the left side of the page. Click the little down arrow, and you'll see "Mute (user)" and "Report / block (User)" options. I don't know exactly what muting a user does, but it might be worth a try.

[@ellmuffin]

I admire your honesty. Everyone, listen, Sitting Guy for President

[@catebrooks6779]

Possibly the best SciShow episode ever... brought me back to reading Cryptonomicon. Good job!

[@EvelynDayless]

When hackers get data it's usually because either they got access to the decrypted data or the company didn't bother encrypting it at all. They don't usually break the encryption themselves.

[@arcclite1144]

I work in healthcare programming. Cryptography up a lot, it's nice to see a SciShow video on it!

[@IronDruids]

Seems to me you can get the same effect as an undecipherable code without it actually being unbreakable. Letter shift the message with the Caesar cipher, code the end result with the polyalphabetic cipher, and then use whatever other ciphers you so choose on top of all that. It should be such a momentous hassle full of trial and error while trying to figure out what ciphers were used that by the time it's decoded, the message is already unimportant with you being long gone and the scheme already accomplished. You bury them under so much busy work that you can do whatever you want in the meantime completely unhindered. Unless I'm misunderstanding how ciphers work?

[@FalbertForester]

You're right in separating "undecipherable" and "unbreakable". Most modern cryptography schemes are sets of rules that are fairly simple for computers to implement. As of yet, most of them are not proven "unbreakable", just "we think that these aren't decipherable in a reasonable amount of time". Which can be "good enough".

[@CultureStress]

I'm a little bummed you didn't finish with a bit about the Navajo Codetalkers. I know it's not exactly "encryption", but it seems relevant.

[@YUSOMEAN]

New and better cyphers, drop some hot bars, bruv

[@JoeBribiesca]

INDEED, ONE OF THE BEST EPISODES OF SCISHOW YET! Way to go, team! And way to host, Michael!

[@AdvosArt]

It's funny cause I just watched top 10 memes top 10 facts gravity falls and at the start he talked about codes

[@amadoudiallo8557]

Omg, me too i was about to comment that lol

[@Digging4AnswersOfficial]

Oh gosh same here...

[@neutronstar6739]

Same

[@stevenroyalton7789]

Holy shet a combo breaker oppurtunity! Jk same here so we are all part of this internet genius club that subbed to Lemino and scishow

[@lfmm97]

This was one of the most interesting episodes so far. Great job.

[@kroen]

If every cipher can be cracked with enough time and determination, then how come no one has yet to crach the voynich manuscript? that book has been around for over 600 years and countless people have tried and failed to crack it.

[@Andytlp]

Kroen Redstone the only logical answer is.. it's plain gibberish. I can tell cuz there was illustrations of people having sex. In a herbal journal of some sort. Lmao.

[@1serhiy]

Kroen Redstone people at harvard uni studies the book and noticed that most of the words inside the book are too long to form a coherent and useful language, therefore they concluded that the book is gibberish and have created a way of mimicking the gibberish via a set of rules.

[@isaackarjala7916]

Not every cipher can be broken, one-time-pads are mathematically impossible to crack if implemented correctly, several other algorithms might also be impossible to crack when implemented correctly, but that hasn't been proven mathematically. Also, you can't translate a language using only the written language.

[@Darticus42]

tulp35000 Maybe there's some secrets the author really didn't want people to know about ;)

[@thatguyitzme5725]

Kroen Redstone jibberish

[@oceannuclear]

The animation team has done a great job on this one!

[@Acq49]

my brain hurts

[@thegingersheep]

As someone who has a degree in Cyber Security I can say that encryption really is a double edged sword. From one site it's a great way to protect data. On the other it prevents through investigation after a breach due to the attackers using their own encryption. Sadly is its one of those situations where many develop a love/hate relationship with it.

[@kathyphilip7925]

Gotta love Alan Turing!

[@Tryangetbetter]

Fantastic video! In my third year of university we had to encrypt a message using any combination of substitution ciphers, Caeser shifts, Vigenere, and affine ciphers before then decrypting each others ciphertext. If our message got decrypted we lost marks and we gained marks by decrypting other peoples messages, it was a fun piece of coursework, especially after making a document in Excel to do all of the manual work for me :D

[@glorvalmacglorvas171]

Here is how to make an unbreakable code: Write down random letters and just remember what you meant. :D

[@288theabe]

The enigma machine was the first thing that came to mind when I saw the title of this episode. Fun fact: There's one sitting in the Canadian War Museum for people to play with and it's mind-blowing how the letters changes every time. But now that I know certain letters can't be used for the same word, I just may spend more time there....until little Susie kicks my ass out of it. On a related note, the Navajo language was never broken by the Japanese in WWII either, but if the atomic bombs were never dropped and the Pacific war stretched on, I think it would've been with time.

[@LukeScottgamer]

Thanks Gravity Falls for teaching me this.

[@Phoenixmage50]

lol for me it was the overwatch arg with all that encryption and salted shit

[@Chriael]

Same dude!!

[@marciparks3377]

Wow Michael! I really love how into detail this episode is.

[@MosukaDreamer]

The guy from Vsause is named michael. Coincidence?

[@SlyPearTree]

Nice episode. I didn't learn anything but cryptography is always an interesting subject. Can't wait for the promised follow up.

[@godqueenbidoof]

This was great I wish you had talked some about Steganography though, which amusingly enough google chrome's spell check doesn't recognise as a word XD

[@EvelynDayless]

Jeff Cyr Hmm, it does for me.

[@godqueenbidoof]

Munashiimaru Really? I guess it's cause I have it set to UK english then

[@General12th]

Jeff Cyr Chrome spell check doesn't recognize a lot of the technical words I use, like "apoapsis". I'm not sure why its dictionary is so limited.

[@heinrichthurston6961]

***** I only know that word thanks to Artifexian. The math may not make sense but it works.

[@Fenriswaffle]

***** Uncommon word perhaps? Usually peri/apo are in reference to peri/aphelion which isn't common to begin with. Also I learned peri/apoapsis from the same place most people did.

[@HalcyonSerenade]

Aw, I was actually hoping for some of the newer, digital encryption information! Fun stuff regardless, though. Frequency analysis would've been my go-to for the standard Caesar cipher, but being able to apply it against a varying rule is fascinating. Human ingenuity is astounding.

[@tuxino]

I'm not really concerned with North Korea reading my email - and unless you're doing sensitive government work and and have documents related to that in your email, you probably shouldn't be either. A whole different concern is my own government or other organizations working within my country.

[@Okaiako]

Exactly, true

[@strifera]

I legitimately just guessed the cryptogram from the start of the episode as "scishow is the best" within a second or two of seeing it with no conscious input on my end. Admittedly this ended up being obviously wrong after a second or two of consideration, but it was so in the ballpark that it might as well be on first base. I'm really proud of my brain right now.

[@jk844100]

Actually the Polish cracked the enigma code first.

[@tomshraderd4915]

jk844100 Yes, it was mentioned in the video at 6:53 under the picture.

[@videogyar2]

***** The british havent decoded it fully either. In the movie The imitation game its highly overrated.

[@TheApollotd]

The polish cracked enigma (easy) Alan Turing (British) and his machine decrypt ed the code out of 159,000,000,000,000,000,000 possible combinations that kept changing every day

[@habiblevi5369]

***** The original Enigma machine landed in a Polish customs office courtesy of Berlin. It was promptly followed by a German official claiming the crate had been sent by mistake, and to return it immediately before passing through customs. This aroused suspicion, so the customs officials took the crate apart and photographed everything they could so that a working model could be reproduced. This was in 1929, by 1932 the Poles had developed a working model and were able to decode messages, but in 1938 Germany made a new and improved model that was no longer breakable in the same way. Poland was able to smuggle all their work to the British just before they were invaded. Without that lucky circumstance, and Poland's hard work, Enigma may have never been broken during the war.

[@Quadsie]

But Britain can into space

[@EcceJack]

This was a very nice overview for those hearing about this for the first time - but also a nice summary for those of us who have heard more about some of these methods (especially Enigma), but really don't mind being reminded of the *big picture* every now and again. So all in all: great job! :)

[@ColtaineCrows]

More interested in keeping the USA out of my e-mails to be honest.

[@alicered4198]

3:23 Vigenere has always been my favorite cipher.

[@MagicTurtle643]

Wow, great episode. I was rapt the whole time.

[@JohnSF93]

I learned to use the Playfair cipher a couple of years ago. Very simple to use, and very hard to crack. It's still possible to do letter pair frequency analysis, but you need a really large ciphertext to even get started

[@DarthObscurity]

Why do things get brittle when they dry out?

[@eightplusone7512]

Because moisture offer more flexible movements and typically when that happens that means it was already pretty brittle

[@laurenford7232]

Remembering the rules of this video helped me figure out a code during a mystery game with friends today. Thanks!

[@MukaMoko]

Would the Rosetta Stone be considered as an unbreakable message?

[@ShaudL]

Um no.... I'd think not at least. I mean we have most of the languages on it learned and we did that by analyzing surrounding languages.... With some time given it'll be broken

[@departmentofeducation7212]

Primid King He wasn't talking about the language learning program, he was talking about the actual Rosetta Stone, which helped us understand the hieroglyphic writing system of the Egyptians.

[@ShaudL]

+Malboro Overking so was I 😂😂

[@ShaudL]

+Malboro Overking so was I 😂😂

[@ShaudL]

+Malboro Overking so was I 😂😂

[@TheBigangrytexan]

Fascinating. Thank you for the video!

[@sunofslavia]

"Nice Things About Hitler" that's a pretty edgy post-punk cold-wave band name.

[@jhosioja]

Would've been a perfect episode to give a nod towards Numberphile, and the fairly detailed, yet comprehensible bits they did about the Enigma, how it works and how the Poles cracked it, and why the Brits had to crack it again.

[@rowboogs1]

My brain just got brain fucked.

[@KarasGamer]

same here

[@cldream]

Oddly enough, there's a language called Brainfuck. ;P

[@israelch100]

I just watched the imitation game yesterday, and this question was in my head the entire day, thanks guys!

[@vinvint]

use encrypted klingon

[@TomKellyXY]

While the Enigma was cracked, the Germans never managed to crack messages from the New Zealand WWII troops who spoke plain unencrypted Te Reo Māori into the Radio

[@IwulikeLOLZ]

+Tom Kelly lmao the axis couldnt really crack any first nation languages. So when they intercepted messages usually coming from the commonwealth they didnt know what they said

[@IwulikeLOLZ]

+Tom Kelly lmao the axis couldnt really crack any first nation languages. So when they intercepted messages usually coming from the commonwealth they didnt know what they said

[@IwulikeLOLZ]

+Tom Kelly lmao the axis couldnt really crack any first nation languages. So when they intercepted messages usually coming from the commonwealth they didnt know what they said

[@vlchltsemsdbscrlbrs8624]

you are looking

[@nERVEcenter117]

Hey SciShow, Alan Turing isn't just recognized as a mathematician, but also one of the founding geniuses of the field of computer science. If we want knowledge and interest in computer science to spread, we shouldn't hide the history of the field or its greatest contributors, especially when the topic of the video is an essential problem space in computer science.

[@przemysawzych1866]

I don't understand why it is so common in English programs/films not to mention about three polish cryptographers who decoded Enigma before Turing. You should have done your research more reliable.

[@luckynater]

source?

[@przemysawzych1866]

+luckynater BBC for example. you can dig deeper but this source seems easiest and still reliable. www.bbc.com/news/magazine-28167071

[@someperson5506]

Didn't know that. Thank you :)

[@dmitrixallo7072]

Because the UK want to glorify their 'Great' country, which is falling apart, and good that was made by other countries, they will take it, whatever they did bad, they give it to other countries. Pozdrawiam

[@mrfriendlyguy]

You guys need to talk about quantum communications, and how it makes it harder to hack. It would go nicely with all this talk about encryption.

[@annikaorly629]

whos here for school?

[@camillaadrain8566]

I~n~v~e~s~t~i~n~B~T~C~~{}~{}~E~T~H{}{}{} W~H~A~T~S~A~P~P +~ 1 ~3 ~1 ~2 ~2 ~1 ~9 ~5 ~0 ~ 0 ~4 ~~~~~........

[@froot3839]

me

[@prahladsaldanha568]

Really well done

[@admin.....901]

Thanks~~~~~

[@Robot_Overlord]

That was one of the best ones yet. Keep going

[@vitalymilavsky9451]

This was a great episode, please make a follow up

[@Kaalyn_HOW]

This gave me such a headache. ...but like a good kind. Like a learning, puzzle-solvers kind. ...awesome.

[@Kpac_]

Learned so much about Alan Turing watching The Imitation Game. Didn't realize how forward thinking he was when it came to modern computers.

[@sakeneden]

This is a superbly explanatory and interesting video about cryptography. Good job!

[@Alifnukman]

i dont even do anything remotely connected to this video, i dont do coding, i never learn computer science, i Dont know a single thing about cryptography, yet, i still understand your video even though its a fast pace video, thanks, now im gonna go to sleep because its 4 a.m and somehow i manage to stumble upon this video

[@misschelz1]

omg Michael Aranda!! It's been ages since I've seen him !

[@vatsalamolly]

I enjoyed this. A brief summary of my Data Security class from college, hehe.

[@RonN448]

Absolutely and utterly fascinating. But, I think my mind blew a fuse!

[@ferrous719]

I read a book once in which they used two Identical prints of a book and a three number code. 12-18-4 referred to pg 12, line 18, word 4. easy to send msgs with common words and nearly unbreakable without the key, especially because you could use different combinations for the same word. obviously wouldn't work for data transfer, but cool for word based msgs.

[@StreetKingEvolution]

Agreed! One of the most interesting episodes yet!

[@harryrussell154]

The Galaxy Cipher Machine: Unbreakable encryption. Then using the Kaliko encryption method. Set up: A disc cipher machine on a spindle, the discs are like checkers in that they have notches to fit into each other. 1st wheel is the set disc with the numbers 1-80 scrambled, etched around the side, and on the top edge are three alphabets, scrambled the same, with two empty spaces to make 80 digits around the top. Each letter on the top is over a number on the side. There are 26 body discs, each having two rows (top and bottom) of 1-80 on their sides. The first message is a four number code: 1234. This is first a security check. The number 23 on the disc, 4 to the right, plus 1, gives you the security response. For the set up: The number one represents which set disc is to be used. The 23 is the number on the set disc that is under the letter on the top "E". This letter is the first body disc to be put on the spindle under the set disc. Depending on what the users invented for themselves, an even number goes left, odd/right. So the order of the body discs is the E first, then of right for the rest of the letter order for the discs. The body discs are like checkers in that they have notches for them to fit into each other. There is a dot on the bottom of the set disc somewhere between two numbers, and a dot on each side of each body disc as well. The last number of the 1234, the 4, is how many (left or right) notches to shift the discs as they are being put on using the dots as beginning points. 4 was invented to mean right for the dots so each disc has their dots spaced 4 notches to the right of the one above it. It is also decided/invented which discs go on up-side down. Once all discs are in place a tightening bolt is screwed on the spindle to secure the discs. Operation: In the coded message sent, the first 30 numbers are still part of the set up. The message follows after them. In these 30 numbers you have invented the pattern that if there are two number 6s in the 5th, 13th, 18th, and 29th numbers, the message is authentic. If there are more or less than two number 6s the message is bogus and is disregarded. In the first 30 numbers, you take the 4th and 9th numbers to know which algorithms to use, in this case both numbers are 12,34. You have invented at least 10 algorithms. The first message letter is O. Find an O on the top of the set disc in one of the alphabets (using another alphabet for the next O), and go down to the number below it on the edge, say 57. Now the first four algorithms are made up by the two users of the machines so they can be anything their imaginations can come up with. Like, from 57, down five discs to the top row of 1-80 where the number is 32, find 32 on the bottom row and go down 7 more discs and do the same, then go straight up to the set disc. 2nd algorithm is a diagonal angling down to the right 8 discs to the lower number on that disc-46, then finding the 46 on the top row, and straight up the to the top set disc. 3rd algorithm is another imaginative pattern ending at the top number 78 on the set disc. 4th algorithm now has a sleeve that fits over the machine with holes randomly drilled into its side lining up with each disc's number lines, 15 holes per line. Now look again to the first 30 numbers and see the 18th and the 62nd numbers are 36, and 84. So now the 78 is lined up with the 3rd disc's top number 6 hole, this shows the number 69 in the bottom number row hole 8. This continues for 4 discs to the last number 51 that is sent in to the other communicating person. (36, 84 is third disc, holes 6 and 8, for 4 discs)They run it all backwards to find the letter O. Throughout the sent message there are many OOs. The pattern invented is that you go six numbers beyond the OO to see if there is a number 5 in that number (75). If there is, you know it is a body disc shift. The other number is how many notches to shift each dot.(Odd numbers one way, even the other). Do this at least once every message. If there is a 2 in that number (27) it means to replace the set disc with another one, in this case the number 7 set disc. You replace the old one and just line up the dots of the new set disc directly over the dot beneath it on the first body disc. Do this at least once every message for both set and body discs. Another code invented tells you to change the entire order of the set up with a 4 digit set up number following it. Another code tells you to change the number of algorithms to use. Golden rules: 1) Never use the same set up code more than once. 2) Always send at least 15 phony messages for every one authentic message. 3) Always shift both the set disc and body discs at least once every message. This cipher machine has ever changing/shifting number patterns, an infinite number of invented algorithms that are used in different orders, a large number of algorithms to constantly change, and every set of machines has a different operation. Each operating set of machines have virgin discs no other machines have. This cipher machine cannot be broken, not even by the largest computers in the world if used correctly. The confirmation that a code has been broken is that the message appears. With a 500 letter message, if 500 GCMs are used where each machine only encrypts one letter, there is no confirmation the letter that comes up when trying to break it is the actual letter that is in the message. Every letter has a machine with different discs, different algorithms, and different operators encrypting it. So the most any attempt to break the code can do is acknowledge that each letter position could be any of the letters in the entire alphabet (A-Z). To write out the possibilities on paper would be to have an entire alphabet under letter position #1, then another one under #2, an so on. In the end there would be 500 alphabets in a row as the only clue to what the message says. A wall of alphabets. Its like telling the hackers there are 500 letters in the message and the words are in the dictionary. With this small bit of information it is IMPOSSIBLE to even begin to try to find the message. Not even the biggest computer in the world, working on it for 10,000 years could find the message. This encryption form is called KALIkO ENCRYPTION, it is unbreakable, and is perfectly suited for the Galaxy Cipher Machine.

[@gnuPirate]

Fantastic video, really enjoyed it, learned a lot in a short time. Thanks Sci Show.

[@Adlez27]

The chipspeech fandom had a lot of fun (read: crying for hours) decoding ciphers that led up to the reveal of a new character!

[@jkkolham170]

Adlez27 Do you want to know what Brock is doing?

[@ma6inka]

One of the best episodes ever !

[@gffypopcorn123]

THIS!! Please do more like this!

[@kinaya6402]

this video was very useful to learn more about cryptography and to encode a message, something that has been very useful to me, because the it's the only way (apart from these commentsw) that i can communicate with the outside world without IT blocking me

[@admin.....901]

Thanks~~~~~

[@joettaxoxo]

This was the coolest video! Thanks SciShow

[@asbestoz1123]

Dude I could see straight through that encrypted message easily

[@chillsahoy2640]

I don't think I'd understand the technicalities of modern digital encryption but I heard an analogy that made sense to me. If you're entering some private information on KZbin, you put it in a briefcase and close it with a lock to which only you have the key, then you send KZbin the locked briefcase containing the sensitive information. KZbin can't open the briefcase, but they add a second lock which only they have the key to, and send you back the now double-locked briefcase. When it gets to your computer, you can verify that KZbin's lock is authentic, so you open your own lock and send the briefcase back to KZbin. Then they see that you've opened your lock, and they can open their own. This way, there is no exchange of codes or locks between the two parties, each side only manipulates their own lock.

[@ImmaterialDigression]

There were a lot of enigma code books stolen from boats/subs which helped a lot with breaking the codes.

[@IsaacComelli]

I would very much like to see an episode on modern encryption. Please make a Part 2, and soon.

[@scottecooke]

Me and a friend had a secret code in primary school. We would write backwards so anybody reading it wouldn't know what it meant. Worked well when other kids tried to read it.

[@ZachTheGreek]

Seriously cool episode. More long form stuff for sure.

[@darbreslin5599]

MicManGuy you had an awesome teacher!

[@youngjoo8091]

I love the way this makes more sense after you've watched the imitation game