Building a Blockchain in Under 15 Minutes - Programmer explains

[@IvanOnTech]

New 2020 version: kzbin.info/www/bejne/anfac3Vsq82corc

[@lizacrowi245]

helloo please how can i contact you ?? i have a lot of questions to ask !!! pleaseee thank you

[@tomassonnlgry9108]

Ivan, your performance in 3 years time is awesome!

[@raajqurashi1619]

Wow nice video ....03155797844 me watsep nmbr

[@computeruniverse6759]

Hi 2021 Russian

[@Zimbob2424]

The link is marked as private . Thanks for the above video. one more step to being able to program a block chain myself

[@TotallyRocco]

I not only want to thank Ivan for the help, coz this dummy just learned some, but thank you all in your posts for being kind to each other, you all communicate and collaborate kinder than most any other threads I find on this YT search engine! Keep spreading the love!

[@deemaak8980]

What I understood from this video is that I'm not a fast learner

[@Saintdog000]

This made me laugh so hard lol

[@Seren2010kinder]

I can morse code

[@dimmoIshere]

@@Seren2010kinder lol

[@emekabronson8697]

How much would this cost if hiring a contractor to develop /complete ?

[@felixwilliams6321]

@@emekabronson8697 1000 to 1700$

[@gaborfzks]

Wow, time fly’s! A young boy becomes a grown man in front of our eyes.

[@Sldn5]

He was 21 years old in this video 3 years ago... he‘s born in 96

[@andrewfinsand891]

He no longer uses the window as a light source

[@aayo_gorkhali]

gaborfzks Werent you young once? Wow a kid once in daipers commenting on youtube

[@gaborfzks]

@@aayo_gorkhali Growing old is inevitable, growing up is optional.

[@aayo_gorkhali]

@@gaborfzks and who are you to judge any one? are you on the level to judge someone? i mean what made you think that you can actually judge a person? earth was there billion years ago and will be some billion years more, its just that you came to earth little early beside that what are you and what you have?

[@TheCryptoFactor]

Ivan: I need some sort of artificial lighting .... fast forward 2020: Industry standard lighting, professional grade microphone... 5 TV sets! Congrats man, you have come a long way, keep succeeding - Paul

[@storm132]

like, subscribe, bell button, all (UACA remix)

[@mjkeating]

The lighting looks good to me.

[@makoes11]

Natural light that's the best when you can use it

[@Hitman78CRO]

You're great! I'm a tech guy my entire life and was never interested in programming. You just changed that! Thank you!

[@jeremyfrancis3274]

Simple and straightforward. Need more people like this.

[@stella245]

I found this video in 2021. It's unbelievable how you developed from 2017. Well done, you're doing a great job!

[@user-vn2hz1xm1f]

T:h:a:n:k:: f:o:r:: w:a:t:c:h:i:n:g: a:n:d::: f:e:e:d:b:a:c:k:: w:r:i:t:e:: m:e:: n:o:w::f:o:r: m:o:r:e:: i:n:f:o:r:m:a:t:i:o:n:: W::h::a::t::s::a::p::p:: +1::9:::7:::1:::9:::1:::0-3::6::0::9:..

[@codygonzalez5131]

Thank you, brother, I put my finger up! You really met in 15 minutes and everything was clearly explained!

[@OSBib2]

Thank you, Ivan! It makes me understanding this technology in Java terms and how to code blockchain.

[@iderik01]

To say "digital signature" is just a way of making it understandable. Good explanation and very clear, Heja Sverige!!!

[@Fadhilx]

after 9++ videos i've watch, this is the one that help me understand blockchain. Thanks man.

[@metavision1933]

the last 2min were the best thing i watched in 2019. great job

[@MauriceLacerda0]

Awesome video Ivan! Thank you so much for putting such a complex topic into digestible format!

[@KashTheKingYT]

This video explained crypto to me in less than 3 minutes

[@greywolf271]

Thanks mate, very concise and clear explanation. I've been looking for exactly this for a while now.

[@nlkoala9292]

do u press ENTER? when u say (run it)? also where can u save ur work? and last question how could I create a blockchain for the health care?

[@Adolphsson]

First two and a half minutes: Ok, this is some very basic stuff. I already know what a hash is. How are you possibly going to explain this whole thing in just 15 minutes? Literally one minute later: Mind blown!

[@AineCara]

This video should be moved up on the playlist. It's very helpful for understanding the previous videos.

[@AmeliaRogher]

I've watched a few videos about blockchain and this is honestly the only one that helped me understand what it is,thank you!

[@EvgenyAleshin]

Great video Ivan, very clear and concise. Would be nice to see you explain Genetic Algorithms and Neural Networks(preferably using Java) and maybe an Evolutionary Neural Network as a conclusion for both topics

[@cwatchman974]

If you understand blockchains I need a developer

[@bobbynewman6129]

I know I'm late, but thank you! This is the best explanation I’ve found of what a blockchain really is. Great stuff.

[@HassanAbdelkerimBouyebri]

“Lets give her this amount 999 of BTC to mom”. She deserves even more. You will be the one who taught me a hash is just a digital signature. Great video. Thank you.

[@techsauce2706]

It's easy to understand !! Block chain adds new information to the chain itself and doesn't re-writes .

[@pinnédby.Ivanontech]

>>T•e•x•t_m•e_f•o•r_s•o•m•e•t•h•i•n•g_n•ew_n•o•w_o•n_m•y•_t•r•a•d•i•n•g_t•i•p•s

[@laurathelion100]

Excellent video, Ivan!! Nice and fast and kept me totally interested. I definitely got a good understanding of how the blockchain works, as only coding can do. Thanks and keep up the good work! -- laura, a new subscriber

[@jankarlo28]

This is a gem. Simplest way to explain blockchain technology at its core. Keep creating good contents, you deserve more than a million sub.

[@user-vn2hz1xm1f]

T:ԋ:α:ɳ:ƙ:: ϝ:σ:ɾ:: ɯ:α:ƚ:ƈ:ԋ:: ι:ɳ:ɠ: α:ɳ:ԃ:: ϝ:ҽ:ҽ:ԃ:Ⴆ:α:ƈ:ƙ:: ɯ:ɾ:ι:ƚ:ҽ:: ɱ:ҽ:: ɳ:σ:ɯ::ϝ:σ:ɾ: ɱ:σ:ɾ:ҽ:: ι:ɳ:ϝ:σ:ɾ:ɱ:α:ƚ:ι:σ:ɳ: W::ԋ::α::ƚ::ʂ::α::ρ::ρ::: +1::(7::0::3)::7::7::5::0::9::3::9:..

[@TheAldawg77]

The lighting is OK bro ty for the educational video!

[@dotrule4115]

Total outsider with no tech knowledge but I understood what you were saying. Thanks, Ivan. Great job explaining. Btw, is there a more elaborate video for total newbies like me to learn more on how to use the program and such ?

[@kennethzambrano5287]

Brooooooo your the big one Master! Thanks for this video. 2 days ago i was asking myself about How to program my own Blockchain from scract! Really appreciate!

[@mayanknagwanshi]

thanks for the most simple explanation on how public ledger blockchain works, I only wish I could have seen this earlier in 2017 :)

[@pinnédby.Ivanontech]

>>T•e•x•t_m•e_f•o•r_s•o•m•e•t•h•i•n•g_n•ew_n•o•w_o•n_m•y•_t•r•a•d•i•n•g_t•i•p•s

[@CsabaTothMr]

"This kind of hash is very hard to crack" - wrong. The example could very well use MD5 or even better: SHA256. Very easy to use with Java. You could claim that it's very hard to crack then. The regular Java class's hash function is not a cryptographic hash function in the sense that it'd be hard to crack.

[@SuperMorrey]

Agreed!

[@gabkov]

+1

[@marcosrun9837]

MD5 isn't really a good encryption method now days

[@CsabaTothMr]

@@marcosrun9837 yes, I shouldn't even mentioned it. But thta's why I said "or even better: SHA256"

[@CsabaTothMr]

@WinterXL If we were demoing a front-end library for a notes example application I'd agree. But security is the most important (!) cornerstone of blockchains. I'd even agree to use the `hash` function for demo purposes, in case the author warns excessively against using it. But saying that it's hard to crack? He may meant that *cryptographic* hash functions are hard to crack... but it doesn't seem like it.

[@persvendsen270]

I`m a Norwegian newbie into blockchain and coding. You explained it great, easy and understandable.

[@iseeweiners3772]

You didn’t search for this. It was recommended

[@user-vn2hz1xm1f]

T:ԋ:α:ɳ:ƙ:: ϝ:σ:ɾ:: ɯ:α:ƚ:ƈ:ԋ:: ι:ɳ:ɠ: α:ɳ:ԃ:: ϝ:ҽ:ҽ:ԃ:Ⴆ:α:ƈ:ƙ:: ɯ:ɾ:ι:ƚ:ҽ:: ɱ:ҽ:: ɳ:σ:ɯ::ϝ:σ:ɾ: ɱ:σ:ɾ:ҽ:: ι:ɳ:ϝ:σ:ɾ:ɱ:α:ƚ:ι:σ:ɳ: W::ԋ::α::ƚ::ʂ::α::ρ::ρ::: +1::(7::0::3)::7::7::5::0::9::3::9:..

[@limborecords2872]

you are 100% right. I'm not too fond of physical mining machines, they create noise, and it's more costly than Cloud mining services. I invested with GorillaGPUs earlier this year and I am impressed. I'm also glad someone came out to speak about them.

[@Mozzthecoolguy]

Ivan, super stuff you made! Thanks a million!

[@suveeer]

I did a little research about them, and they are very legit. Thank you for sharing. We hope they are featured, so we can see what their farm looks.

[@FusingDifferences]

Amazing video, thank you, I'm a junior developer myself and was interested in how it would all work and your video has shed some light on this. I can see where this can go from here. My guess is, when a genesis block is created and verified it is distributed to what ever network is specified, then which ever block handles a new transaction verifies it by checking with all other blockchains in that network. if its correct (no edits are made) the next block accept/added and distributed again and then on and on. In the case of the other block not being verified it gets rejected and those transactions don't get added. I know its hard (probably impossible due to the verification checks before a new block is accepted but humour me) what if some how two networks of chains within the same system get created somehow, will all transactions cease? how will anyone know which network is the correct one and then move on. Anyway, you've gained a new subscriber, as I want to learn more about this. how you make more and expand, maybe teach a blockchain class or something for programmers

[@bLiNdThInG1]

I think automatically the longest chain is accepted as the correct one. If an incorrect chain is created by someone it's incredibly difficult to sustain it and keep making blocks fast enough because of the computing power required to beat the rest of the network. So normally the correct set of transactions defaults to the longest chain.

[@penclassygiftsthecrazypenl4171]

longest meaning most transactions or created the first or older?

[@mypouf]

Longest meaning the chain with the largest amount of blocks.

[@shubhampreetsingh8630]

Leighton Jacobs you're right bro..

[@shubhobanerjee1681]

But how can I confirm the length of the blockchain from the implementation point of view? I mean it is possible for someone to change the transaction and hash it and make it some nth(some large number) transaction, right?

[@ramachandranbaskar799]

hi, sir how to ethereum using java in eclipse? if possible or not sir

[@dennispagan9542]

Thank you, handsome boy~

[@andreagrasso1072]

Wonderful, following you since 2018 !

[@mitjadecman6729]

Just a note about the terms. Hash is not a digital signature. When you encrypt a hash with a private key, then you get a digital signature.

[@xandriaxanerchek4828]

That was REALLY interesting and easy to understand. Thank you. Have subscribed👍

[@Sarah-dx5zz]

Hey man love your videos! Would you happen to know how to deploy your own blockchain and create a mainnet for it?

[@andrewroberts4666]

One of the best explanation of the block chain... Awesome man!!

[@lyricsofheart5245]

I have heard a lot about GorillaGPUs, and I will start today. My friends are making money with these services.

[@JohnSmith-bx4gf]

dijital signatsur bliet

[@christianjud9827]

Been trying to get this basic concept for a while now. Thanks for your much sought after knowledge.

[@alphamalemc5352]

Ok! How many people got it and how many people did not get it? Your comment below.

[@theRPGmaster]

AlphaMale Mc5 Got it partially, some aspects were not clarified - but I think this was only due to limited time/for the sake of simplicity.

[@Maggie-bd2mi]

Didn't get it

[@perweezneqqi4049]

AlphaMale Mc5 don't understand a damn thing

[@halloherb]

sort of got it, except who verifies that the hashes remain the same throughout? If my hash compares with the next guys' but then it diverts with guy/girl # 4, what happens then? who polices it? have to dig more into it. Good start for me, though.

[@whenagain185]

like comparing pieces to determine if it matches 100percent, to verify authenticate the data. like a password? it's just buying into over complicating things. maybe you should use your smarts to create a simple process. that's how you bring humanity together, if we all get it! verses too complicated and people are like whatever and that lack of understanding becomes power

[@superconsultant99]

Really good video! But some questions you answer there, raise more question. So it would of been really great if you could elaborate on these: 1) When some one sand coins to someone where does this transaction request goes: is it being broadcasted to every registered miner or it goes to some intermediary computer where all the miners get it from. 2) Does the bock of particular coin always has the same number of transactions or it varies. 3) how is it enforced that miners put the same transactions in the same block. 4) where the transactions stored before they make it into a block(in a sql database or flat file or else), also where are the blocks saved(in a sql database or flat file or else). 5)How is it addressed, if for example block # 12 in blockchain and block # 3098 produce the same hash value or does it matter at all as previous block has value is also taken into account. Sorry for the long comment/request, my list is much longer, but I already feel like I am abusing you good will, so I will stop here. Once again thank you for your videos, they are very informative and straight to the point.

[@amiramnoamdoron]

your videos is absolutly awesome, the smoth talking the clear expelation the topics, thanks Ivan!

[@kpeter4979]

Thanks! Your new subscriber.

[@IvanOnTech]

welcome my man, glad having you here!

[@hoat23]

Your videos are very good...I am a new subscriber, too.

[@mohaneesh]

Superb explanation and coding demo of a difficult concept. Thanks Ivan. Keep your videos coming. And the lighting is very good. No need to adjust the curtains.

[@neeleshagrawal]

Loved it. Thanks mate!! Keep Going :)

[@chucknor9708]

This video gives a really good demo of a blockchain in action. Seeing some code really helps in understanding the concept.

[@mrguiltyfool]

Can you upload the code?

[@IvanOnTech]

boom github.com/ivan-liljeqvist/SimpleBlockchain

[@JonathanAdami]

yeah you wouldn't wanna type all of these 4 lines all over again ;)

[@AntonioKowatsch]

LMAO

[@1999owned]

BAM

[@agustriberry9936]

Ivan on Tech So, it's using a class for store a data previus and for futher it using for hashing to make a blockchain, can i useing Linkedlist method, or stack or another of memory store techninc?

[@funmeister]

Well done, brother. Following your code was spot on, but the greater benefit is just showing it and giving viewers a glimpse of the process.

[@marceloroitman6704]

Thanks for this great video! That's a classic scenario when greed and ignorance are meeting. I have friends buying Cryptos without any minimal knowledge what is a block chain! GREED and IGNORANCE, I'm sorry about them.

Please explains how the mining process works.

[@moea.9120]

Do you know how to make a complete cryptocurrency? We are looking for a developer for our project... let me know, if you might be interested.

[@moea.9120]

I'll pay you $10,000.

[@Manrulz]

I can assist in your project? I've got 2 years of coding experience and have been helping with a few other coin developing their project such as $BUZZ

[@paalzolder]

Lol why should you pay someone 10k when he offers only 4k? As a business that would be very dumb lmao

[@NurseReign88]

Came by, So helpful, just subbed, please make more videos about establishing a blockchain network for decentralised peer to peer consensus and innovation 💡 😀 👍 🙏

[@trumberak]

Thank you Ivan. Your intro to Blockchain is the best I had the chance to see. Have a nice day.

[@tellyrotsyourbrain]

Great description of what is at the core of a blockchain. Suddenly a mystery is solved. Thank you so much!

[@Duuvallll]

Solid upload, pretty straightforward and easy example to grasp from someone with no programming background. +1 Subscriber Keep up the great work!

[@CaspermeansTV]

You've opened my eyes on blockchain technology. Thank you so much!

[@travisdetert1034]

Hi Ivan! Great video! I've been following these concepts for a bit, but I haven't dived super deep and I stumbled upon your video. Excellent explanation! Cheers man!

[@RuzoOwzy]

How hv u reached so far after 4 years?

[@alexozorio8090]

Hey what’s up Ivan. I’m beginning to start learning how to code and I was wondering if you could help me figure out a curriculum so I can learn the proper steps so I can come back to this video and completely understand. Thank you for what you’re doing for everyone.

[@Jerrel.A]

Showcasing this example is very elementary for understanding the technology. Thx!

[@mdmonzurmorshed3557]

Very good video. Can you upload a video for building proof-of-work using java?

[@user-vn2hz1xm1f]

T:ԋ:α:ɳ:ƙ:: ϝ:σ:ɾ:: ɯ:α:ƚ:ƈ:ԋ:: ι:ɳ:ɠ: α:ɳ:ԃ:: ϝ:ҽ:ҽ:ԃ:Ⴆ:α:ƈ:ƙ:: ɯ:ɾ:ι:ƚ:ҽ:: ɱ:ҽ:: ɳ:σ:ɯ::ϝ:σ:ɾ: ɱ:σ:ɾ:ҽ:: ι:ɳ:ϝ:σ:ɾ:ɱ:α:ƚ:ι:σ:ɳ: W::ԋ::α::ƚ::ʂ::α::ρ::ρ::: +1::(7::0::3)::7::7::5::0::9::3::9:...

[@onlineclasses3525]

finally found the satoshi guy😶😶

[@babizonk3294]

Great video. What programming language is ideal for blockchain technology?

[@RichardServello]

I think SciShow explained hashes in the best way I've seen. 1+2+3+4=10. 10 is your hash key. If you enter the data set it will always equal 10. But you can't get back to the data set from 10. It could be 2+4+4 or 1+3+6 or 1+1+1+3 or 6+4 etc. With SHA256 your data set equals an alpha numeric 256bit hash....making it basically impossible to get back to the data that created it, your private key.

[@ReifenSchoen]

Great Video! I'm new to blockchain and still trying to understand. Thank You! Where in your explanation comes in the concept of mining? cheers, Paul

[@valvlog4665]

Great explanation. Thanks. Of course, I'm left with the basic Q's. Maybe you can have a shot at some. 1) So where are the repositories for all these blocks? If this was an RDB or a web server, someone would be hosting it. Who is hosting the block repositories? And who makes block repositories software? I see Oracle are launching a blockchain platform soon. 2) How many copies are there? Who regulates how many copies? In a RDB world this might be called replication or shadow copies. 3) Who decides which copy is the truth, if say there's only 2 copies and they're in contention? The low level stuff is of course loved by geeks. The high level infrastructure though in which the cool code lives is just a important.

[@Jacob011]

Nice hands on example, though you forgot to mention the important fact that this chaining process is happening in many places (i.e. on many nodes), as I understand it. Thus when someone hacks one node and tries to change the transacted amount, the change propagates on that node's copy of the blockchain. And so when the one node in the network has the corrupted version of the chain. The other nodes however have the uncorrupted version, and since there is more of the uncorrupted ones, the consensus lands with the uncorrupted ones. The network then resisted the attack. One can then easily imagine that in order to force their own ill will into the network, they would need to perform the exactly same change on at least 51% of the nodes. This is why you hear about "the 51% attack".

[@Yovry]

are there any videos out there that can explain how to develop a mining software such as the EWBF miner or CG miner that connect to a user inserted pool or pools?

[@ivanontech9437]

If you need any further details feel free to text on WhatsApp[phone]now ASAP

[@BENIMARU__0]

I am trying to remember when I last used physical machines for Mining. I will stick with Gorilla GPU's live cloud mining services. They are the best.

[@christymathew9035]

YEARS OF SEARCHING FOR A SANE EXPLANATION AND VOILA YOU .. YOU ARE LIKE THE GOD OF BLOCKCHAIN TO ME NOW. I'VE WATCHED MANY GUYS BLABBERING UTTER GIBBERISH AND YOU MADE IT SIMPLE LIKE CUTTING A CAKE WITH A KNIFE. THANK YOU SO MUCH IVAN. LOVE AND REGARDS FROM INDIA.

[@ivanontech9437]

To help you grow your portfolio okay

[@Indian1947-o1z]

great explanation, thanks Ivan do you have blog for beginners to learn blockchain

[@kennethbishop3188]

Brilliant lesson. I'm not a coder but I understood this process. I assume a hash can be performed backwards all the way up the chain to reveal the genesis block? I want to create block chain apps for phones and tablets. What do I need to learn?

[@derrazkhalid]

Pause - dont worry for the light mate, you shine like a hero, thks for the vid - play

[@timomoebes]

Really nice explained and easy to follow up. Thank you very much for taking the time to produce the video! Can you let us know which app you are using to work with JavaScript? I cannot see in the video which app you are using. Thank you :-)

[@python_tutorials6519]

Never thought anyone can explain this detail.Thank you so much

[@babapro6882]

Hit the like button if you are using GorillaGPUs mining service and watching this! I really can't deal with spending much on mining rigs when I can use THF online and make them the same rewards.

[@totoriri6973]

a hash is not a signature, it's just a hash (sometimes referred to as tag also). A signature refers to a signing operation using asynmetric crypto.

[@jordanshroyer138]

This video was a helpful introduction, but what was the purpose of line 24 in Main, where the ArrayList blockchain is declared? You use main to create blocks, and you have to manually enter the hash of the previous block into the constructor of the next block. This creates a chain of dependent blocks, but you don't actually create a blockchain data structure. This was a useful video, but it's incomplete.

[@danielciontut5891]

Question: Theoretically, would it be possible with future technology to change the genesis block or the first block of a chain not only on your block chain but on everyone's blockchain?

[@gasbarocco]

your video are very interesting, i don't know anything at all about programming and coding and stuff like that, but with you i'm starting to understand something :) good job

[@pb9381]

Just stating the obvious for understanding purposes. You can decrypt the hashes in the blocks with a key to reveal the transactions vice versa to the way it is encrypted block by block

[@MuratYlmaz1903]

Easy to understand , sample is perfect for beginners, thanks ivan.

[@codewithayush244]

Nice work but correction is required at the time of changes in transaction you run code again the object can be created at different location in memory so instead of changing and then running it must be shown by changing the transaction array and printing the hash code before modifications and after modifications.

[@sergiyrudenko905]

It was the best explanation of the concept on youtube! Thanks man!!!

[@kausikmalakar2999]

I am an experienced Cobol developer but finding it extremely interesting

[@tobiasgarreton3705]

Awesome video! Best explanation I found out there. Thank you Ivan!

[@user-vn2hz1xm1f]

T:h:a:n:k:: f:o:r:: w:a:t:c:h:i:n:g: a:n:d::: f:e:e:d:b:a:c:k:: w:r:i:t:e:: m:e:: n:o:w::f:o:r: m:o:r:e:: i:n:f:o:r:m:a:t:i:o:n:: W::h::a::t::s::a::p::p:: +1::9:::7:::1:::9:::1:::0-3::6::0::9:.

[@BossTonComedy]

Subscribed! Learning to code right now... my first language. And your content is awesome. I’m going to do an ICO one day for a startup

[@saimondal]

Well described with in 15 mins. do you have any other videos for Blockchain concept?

[@cryptcademy]

Thank you so much for the value bro! Keep them coming

[@VishalChauhan22]

best video to understand blockchain with simplest example, great work 😃 did you buy the virtual light yet ?? 😂😂

[@James-st9uu]

Ivan you are a legend. Made it really clear to explain the security of the blockchain. Can you do a similar video on other consensus methods like Hashgraph and Tangle. That would be legendary. Thanks mate.

[@jamesluckhurst4798]

The first one contains the salt and pepper and the next ones are the pepper / salt based on the last one and so on an so on... The data itself isn't actually encrypted it just verifies it hasnt been tampered just like a software download hash on byte size Why not just create a database with a hash of all the items in a recordset and the last one as the salt and store it in as a extra field for verification for alterations (basically a checksum)

[@mzulfadh]

Thanks dude, you make it simple for us. Great job!