NEAR Whiteboard Series with NEAR | Technical Deep Dive Sessions, 15 Jun 2019

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From YouTube: Whiteboard Series with NEAR | Ep: 20 John Pacific from NuCypher |

Description

Our co-founder Illia Polosukhin (https://twitter.com/ilblackdragon) is in conversation with John Pacific (https://twitter.com/__Tux) from NuCypher (https://twitter.com/NuCypher) in the 20th Episode our the Whiteboard Series that took place during the NY Blockchain Week.

Learn about NuCypher: https://www.nucypher.com/

Location: New Lab Building 128, 19 Morris Ave, Brooklyn, NY, ETH New York | Consensus Week 2019

Download the video here: https://near.ai/64292

------- About Whiteboard Series ---------

The Whiteboard Series with NEAR is a set of video interviews with Founders who are building scalable solutions for Blockchain. We deep dive into their story, what they're developing and how it is helping the ecosystem.

Follow the latest from NEAR Protocol on,

Discord: https://near.ai/discord
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GitHub: https://near.ai/github

#WhiteboardSeries #FutureIsNEAR #Consensus2019

A

Hi everybody amelia was near protocol, we're here actually at East, New York right now and recording a whiteboard series with John from new cipher. Please John into yourself and I can dive right in sure.

B

I'm John from decipher also known as tux I'm, a engineer at decipher, and we build audiences protocols and yeah for decentralized applications in distributed. Applications that allow people to achieve more privacy and more security. Awesome.

A

How does it work sure.

B

All right so, first, the basis of our network is called proxy week, so I'm going to go ahead and just dive right in and explain what proxy richness to give you an overview.

B

Will c-p-r eat, let's just proxy read in fiction, so what I'm just gonna die great, it's out a little bit so normally we're very familiar with Alice and Bob's public key right. So we'll say: Alice has three key out salt, a couple speed and then Bob also has this.

B

So what happens with proxy encryption is actually this transformation from when we encrypt something here with Alice's public key and.

C

B

Can encrypt some data so we'll call this like an encryption function here and we pass in a table with some data like this, you say we get C, so C equals increase the encryption of this data with Alice's public key, so C. So this is what's happening here. Is that alice is in fifteen data with her public key and typically, what we know is we also have her private key and so Bob also has.

B

Private key as well now, if all supposed to decrypt this data, normally she would call a decryption function using her private key on this yeah.

B

Holly race, this really quickly moving on so now we have like this. So this is an asymmetric encryption algorithm and, as you can see, what's just happening here is that alice is calling the scripture on this encrypted cipher text with her private key and getting that data out the secret to here. This is the basis of what we called. You know: public key cryptography and everything.

B

So what we're going to do now is explain how proxy the encryption works with this kind of thoughts actually setting, because everybody's familiar with alice encrypting data and for Bob and Bob in 1584, back and forth, but proxy encryption allows us Alice to encrypt data with her public key and then delegate access to a ciphertext to any person she she wants yeah. So, with this in mind, let's go ahead. Oh thank you. So we'll leave up this first function here see a and what happens is we also have a delegating okay.

B

Now we call a reinforcing key, so we'll go ahead and explain how everything fits in here with some algorithms that right here for oxy encryption has five five different algorithms. So we go one, this is key generation, so we'll call it. He Jim mm-hmm.

C

B

No one that is a encrypt.

B

Third, one decrypt.

B

Fourth, one: this is rekey GERD.

B

If this one is re-encrypt.

B

So go into exactly what each function takes does, but key Jen is pretty obvious: it just outputs a new.

A

B

Just a new key like that and Chris is very obvious, giving the input of a public key and some data each weekend in ciphertext and.

B

Then, on decrypt give an input of a private private key and some ciphertext.

B

We get our data and then enric again. This is where proxy ranking kind of gets, like it's big, interesting component, is that we can actually generate in Ellucian umbral. So I'm going to go over there's a variety of proximity of columns, but what new cipher use is called okay, so all right, this was developed by a by one of our photographers David. Yes, so we keep it here. It takes Alice's, private, key and then Bob's public key and on the output we actually get weirder like shared, so we get in this case.

B

Actually, no I'm gonna extend this actually I'll. Keep it simple for now, just talking about recued in an.

C

B

Yeah on the output, we get what we call a rekey and we'll say this goes from Alice to Bob, Bob, okay, the green crypt simply takes this Oh Ricky.

A

Yeah and ciphertext.

B

On the output, we now get a seats architecture. This is food for.

A

You Alice's key.

B

Yeah there for, like somebody else, this on the output, gives you a cypher text from o P. So.

C

B

Happening here is, when you close being cryptic you, those men could function. Its transfer me transforming the ciphertext that's encrypted under Alice's key to Bob's public mm-hm.

C

B

Bob can decrypt it with his own private key just like in this function here. So unreal does things a little bit differently in a new cipher. This actually isn't secure in the setting that we need, because if you know, obviously we don't want somebody to have a component that is both Alice's private key and bombs from public key right. So because, if you know Bob's public key, you can usually derive Alice's private key from that thing. So what we want to do is make it secure in a decentralized setting, hey.

C

B

Use threshold cryptography to solve this problem, so I'll get into that a little bit later and so I'll just draw an arrow here for threshold.

B

Sorry, my handwriting.

B

So what we're going to do now is explain how this kind of narrative fits in here. So we have a cipher text of Alice and she didn't say: Bob Bell wants access to this cipher text here. So what alice is going to do else is going to call this function. Leakage in.

B

She's going to pass in her private key and Bob's public key and we're going to get this. This remainder here is this I just caught our K.

B

All right so, with this read encryption key that we have no now.

A

Kanakaria exactly.

B

We can just do all this run through the same thing we do here. We do read equipped with.

B

Okay, a defeat and this ciphertext, and so we're putting in Alice's encrypted cipher text, Berger Keith and in this be encryption key and the output hit C be. What just happens here is what we call like an atomic transformation, meaning in no point in time is the cipher text actually decrypted. The ciphertext just gets transformed from one side.

B

There's never actually a another. There is no private material revealed yeah.

A

B

So now Bob can simply just do if he wants to achieve this data. He just calls man.

A

French King yep.

B

With his and then C like that, not way nothing is ever revealed and.

C

B

New cipher is in network that allows people to do this, so it's perfectly decentralized applications where somebody needs to control their key like they have control their data, but they don't want to. They want to delegate access to it. So sometimes people are familiar with the key management kind of thing right. So in key management. Typically, you encrypt the secret story somewhere else, and then you just request access from somebody else, so in this case possibly potentially fix that really well so fulfilling at the app and say you want to share data with that application.

B

Typically, just want you just encrypt the data using the noose after network, you can delegate access to that application or another person, and then they can be cryptic using the mountain, so network will transform that ciphertext. So.

A

What would be like a use case like an example of application to use or.

B

One use case we have is.

B

Your patient and you have a doc I'll, see you move somewhere and.

C

B

Don't want your old doctor having access to your information, it's.

C

B

A climbing yeah.

A

B

More medical privacy, especially yeah.

A

B

So in that case, you can delegate access to your doctor to have access to your medical history, and if they, you know, if you move away, you can revoke a.

A

B

So, in this case, what this looks like here is that this ring trip here is actually stored by a third party outside this region is done, measuring, performed.

B

Before my third party, this is also the new cipher.

A

C

B

C

B

Exactly so nodes in our network stake are token. It may earn the a bit made earlier. The inflation rewards by performing rien Krypton's, so there's a few little problems here, low immunity, I'm going to explain as well and how things work like this, but to solve a fundamental problem. We have now I'll just explain how the threshold, apart of your part, works.

B

B

So we'll be modifying the rika-chan function, just a little bit to put out ever venture I'm sure your super chain, it's a very simple concept, the other secret. So let's say.

B

B

Some secret, usually you know, people use this a lot with yeah.

A

Come on to say.

B

Yeah, so we also- and we say, I need I would say: I need three shares out.

A

Of five out.

B

B

So we have shares.

B

A

As a data back the secret back.

B

Hold- and this is the total yeah.

C

B

The new sniper Network, we call these valleys in the vid secret sharing, so we'll call this here, M so without explained now we can do the same thing for this Rhian shinky that we generated here when we input that is the secret okay.

B

B

So this time I'll leave room myself.

B

Jin I'm input we take our Alice's private key Bob's public key in our national will say three to five.

B

We get mr. Kearney.

A

A

So is it this reek? Ahn is done by Alice in this case, right.

B

We generate five different, which EPA chairs and each one. This is what the privacy of that is, each share alone. Yeah.

A

It's not enough yeah.

B

So it's not alone, so we cover the entire secret. So this is what we call collusion resistance where now it's really firing nodes in our network, even if they did recover the secret they.

A

B

B

So it our nodes, we've both on the network by the way revocation, is simply just talking to know it's a to leadership. Yeah.

C

B

It all we need is just a you know, maximally threshold, so in this case we just need three shares of these five to be deleted and nobody will ever have access to that. So what happens now is that Alice is going to delegate access to, say, hey, it will have five minutes and.

B

Five minutes.

B

But each one is given a share: yeah.

A

So she's just fine squirmer, pretty much. Take your cypher token.

B

Based on how much somebody state or now so what we do is we select a random sample and then so we use a theorem for this, not really a requirement. We just need to have some.

A

B

And then she says she tells the Bob, so Alice now says all right: I'm gonna find a bag, and so since she generated for Bob here, what happens all right?

B

What happens is Bob will simply go to the network, and we'll put this is like, since we know that our network has multi heist tons of people in it to avoid drawing out over and over I'm. Just gonna call this like just one big box, the network.

B

Hopefully that doesn't confuse anybody, but Bob would call a function and what happens? Is he just talks to the network here and on the output he will get was essentially a ciphertext through himself. So what he does is he sends this component? You see a snowball is actually so.

A

Bob sent us yeah yeah.

B

So Bob will say sorry.

A

Alice sands, pretty much to Bob mushy, a yep.

B

Alice encrypts data man.

A

B

She gives this to Bob. She can swim this on like ipfs, whatever she gives this to Bob and then Bob can just go to the network with the CA and each node on the network performs this re-encrypt with a shannon and then at the end. Bob does like this whole combination.

B

Typically, when you're super sharing scheme, we performed that combination and you recover the secret, so he only gets to actually pick so there's three different back notes, so in reality he's actually only picking like a certain subgroup of this. You know to be here: yeah, whatever right. So there's a plenty of notes like now I'm, depending on how much you change usually is we go to network.

B

So now what he hasn't read for this key. He just calls that decrypt function with his own private key, just like.

B

B

So there's a lot of different applications that, obviously you can go with something like that: we're planning on adding a lot more features other than just proxy, which you know people are really stoked about. We have our test set up and yeah.

B

A

Please so so this so first question here is pretty much. You need just nodes right means just network, because you want to revoke access, because if you never wanted to revoke access, you could have just Alice done this. Send it to Bob. Bob now has access to.

B

A

B

So it's like a weird: it's like it's.

A

Like yeah yeah.

B

Yeah wait so, if you just imagine like this being like just a component of each key yeah.

A

B

We obviously don't want to give Bob access to them. He'll be able to find with. If you know, is the reading, 15 you'll be able to derive I'll subscribe. So that's why we split up yeah, but.

A

It's three coordinate somewhere. He said it's recorded on etherium cool gods parts because Bob needs to know. I also cool has the part right.

B

But we yeah, we actually need something. We call the treasure map that tells Bob where to go, which knows have the fragments and.

C

B

Have something called a dirty loop so that he can learn about the network, say where'd? It go yeah.

A

So they can like find out who has the parts.

B

They cared, but otherwise it's synonymous synonymous so.

B

A

Mean you just deploy a contract on the city, I'm, saying food, a piece of fat of this three encrypted A to B and I'll pay like cities.

A

B

So you know 30 years like x, 3p, 98th, district yeah.

A

It still need to be about well, so I'm, I'm, Bob right in this case.

B

A

B

A

Yeah well, the question is pretty much: what's the prize data right, if the prices million this is actually well.

B

If the prices of million dollars, what you can do is up these numbers really high, so that suddenly actually no.

A

Okay, but I mean this question here is also like you have Alice who may be selling a lot of data to all kinds of people, and you bought like some $10 data yeah, and it was you know really cryptid by you know five guys, but then you go bribe them recovers, a very key. You have the private key for you, so you and now you have.

B

B

B

B

B

Decentralized application, yeah.

A

B

Yeah this node so.

C

B

Network we are on pulses, have a time component, which is how long they can last for.

B

A

To regenerator.

B

You don't need, if you don't want some regenerate, you don't have to be here. We both the access and you'll pay for any further time, you'll just pay for the time that was yeah, but.

A

Like like, if you're doing this, for a key for like the data, is actual some private key for accessing something, then you need to regenerate it like we do the private key, because I love the access.

B

A

Mean like if your data is actually a private key to you know like.

B

A

Like this is a maker you know, I make a control control key right and you like yeah, you have. You know a servers that like doing stuff that you're giving a access you know for a months, and then you know you're like actually we don't want to just server to have access to this, like they kind of could have kept it somewhere. If anything else is like in the cache, so we're.

B

Actually, not because yeah.

A

Yeah I mean if you can like fresh out the key in like some more customizable model.

B

B

A

Updating the data there.

B

For all for rotating the like an encrypted private yeah,.

A

B

Actually, supper.

B

Models for encrypting private keys for actually people, no security, it's just adding the security components. We have to really understand what they are first on, so that we know how to build these without people. Music, ok,.

C

B

This case we've tried our hardest to prevent this kind of thing, because we don't think it's a proper security, stop yeah.

A

B

I'm sure you've probably heard the term like this use resistant photography, which is like it's like.

A

You cannot use it.

B

A

Somebody can recover Predaking.

B

A

B

We try to build.

B

C

A

B

That's like the fundamentals of proxy reading picture, but now link itself is actually just really simple. It's just a state.

B

It on the output, so each something I will explain here is like just imagine here. This is one node and these are all different and they each have a repeat right there and.

C

B

Bob calls his retrieve.

B

Each one of these he's passing along some cipher text right, yeah.

A

B

Happens is on the output. They actually get like.

A

A bar show yeah.

B

So we actually call I seen.

A

Yeah Frank Mentos, okay, right.

B

Yeah, so what bob has to do again? I'll say: let's listen to like a combination, function.

B

With the sea frogs on the output, that's when we get to see.

A

What photography behind combination function.

B

A

B

A

B

Component is just news: yeah.

A

Schmidt's parts, and then this is like as if you were aggregating signatures.

B

This case yeah.

A

And only three out of five.

B

A

So if let's say Bob is like you know, querying some of those real estate, guys in San was engine domed respond. Is there any repercussion for.

B

B

A

Didn't confirm Acadia.

B

A

Just like ping, pretty much like ping yeah.

B

There is no way to actually know the.

B

Online there's ways we can build around this to kind of determine if a node is online by having them perform some functions, but they all don't really achieve the same like level of security that we actually need for it by.

A

Like white, so let's say you have a smart contract, you Bob, just you know, adds ch8 or like whatever hash in idea, rosen, ipfs or whatnot, and then just guys add C frag just touch it. Then you see if they add it or not. During some period of time,.

B

A

Like Bob ad said tried and you know, pays for it, for example, and then you have.

B

A

I mean somebody face yeah, but like pretty much, you have Sam to commit see Frank on a smart contract. Well.

B

With the promise we don't.

B

A

B

So once this see frogs were all in a smart contract, then Bob dances.

B

So for some people that may be okay in the Frog protocol.

B

Not really not, really, you know, between the parties too, heavily.

B

A

I mean yes, you do it off chain, but, like you have like bump, has the same information so like you can just store it in like his logs or whatever.

B

A

Don't want to discover.

B

B

A

B

We don't know, I mean.

A

You can store hash or whatever in a hash of what you did and Bob Bob is a pretty much if they try to just put a hash that they did not give to Bob. He can actually like I like you go into arbitrage, military.

B

B

Likeness and reliability factor because ideally we'd be able to say yes.

A

You should kick them out. Yes,.

B

What if, instead of providing the proper nutrition.

B

A

They could have even just.

B

That's a problem: they will go into the solution there. We use zero dogs groups was.

A

Our income is correct, yeah, so.

B

We so imagine we have our rink ripped in the unreal scheme. So again, this is another unreal specific thing here.

C

B

Call re-encrypt I said it took a rekey.

B

It took in cypher text from Alison yeah and then so on the output. We don't just get the see Frank that we call it. We actually also get a we get our C frog from to be, but we also get fruit.

B

All right, this proof.

C

B

On employees take a proof Pete and we take the C fried Bob, and you know we just get a zero. You know just playing yeah.

A

Correct in character.

B

B

Instead, we can actually go to a smart, are.

A

You gonna report the site signed, see Frank. Who is this proof.

B

We can verify it unchanged yeah, so we provide the proof and the signs see Fred, and this thing we call it an adjudicator. This thing tells it to punish it like that.

C

B

Then you know usually what we say. This is like a very serious offense.

A

B

B

A

How long is this proof takes to compute? It's.

B

Actually, it's not traditionally in the space, because EK start, like some other, really complex protocol, but this is such a simple protocol. This a tree encryption is technically only an elliptic curve. Multiplication.

A

C

B

Similar to a signature verification so because of the mathematics is you can use something called snorky.

B

In all of those I should say similar.

B

Same way, so yeah this piece is no proof that can be verified on contract, so we're actually performing this. You know the same calculation here.

A

A

And how big is this proof.

B

A

Any amount of data pretty much.

A

B

A

Only need to run the defending.

A

If people start doing ins, they get slashed and yeah yeah.

B

Have fun throwing your money yeah.

B

A

Prevent it, yeah I mean it yeah. All the slashing is prevention, it's not like unless, unless somebody actually like gets a lot of money out of it, yeah.

B

Yeah, that's that, like I said.

B

There really is no serious answers, probably been looking for other protocols.

A

Or, like just agree, I agree just say a fly.

B

A

That's always like.

B

It so far we're still looking for just really serious I mean.

A

But it's pretty much. You need some kind of consensus actually on this.

B

We don't think this will be an issue. Are sneaking partners really really great people we're going to keep.

B

Think it will probably be one of the most robust networks so.

A

Yeah, it's more like guardians. In a way the stones are like guarding, just pretty much fragments of keys, and then they yeah yeah.

B

Another point here is that you know, since these nodes are you know reliable things. Let's see if we have an unreliable, don't worry what you can do is simply up the threshold limit, increase, yeah.

A

B

Yeah and then you'll actually get you know, it's all fine, that's like the short term yeah. Obviously we are trying to find a solution really hard for that. No, it's a hard problem. Yeah.

A

I know it is I mean loudness is our problem everywhere. So cool yeah.

B

A

Really cool I mean I'm kind of interested, what's happening underneath here, just like as absolutely I, don't know so.

B

I don't want to get into the specifics of how.

B

Okay, so you can imagine, this is actually the very beginnings of proxy reading future came from PBS is paper is published, Manx.

B

And this created essentially P all right, so this is where this is perfect.

C

B

Doesn't it solve clarify just again uncle doesn't do this because clearly, in this case, a Rheem Krypton case of component with Alice's private key Bob's private key, we don't want Bob.

B

So we don't do this, but I'll show you how it works, because then maybe you'll get a feel for exactly what's going on so I know, Riku.

C

B

This case, let's say: Alice wants to generate a real kitchen key from Earth yeah, three keygen.

B

Will then take a component of Alice's private, key and Bob's Frankie? Again, we don't do this inside.

B

So on the output of this we get a math math equation very similar to just.

C

Just like that, Bob Bob's.

B

Private key / ask.

A

Him up multiply advisor encrypted message, a pretty much like Premila.

B

A

Like I private key.

B

If you have a typical key or like sub message where it's like you know some random s, that's encrypted with.

A

You know Google, there's like pretty good article.

B

A

B

We've actually created this ciphertext. This actually itself is the cipher text, a cipher.

A

B

New cipher is the private key, I'm Bob. We do something differently here, but yeah so G to the RA times. P / goes up to the RV. That's that it's very, very simple. So this this right here. This multiplication is the re-encrypt yeah.

B

That's really good, hey.

A

This this is yeah Kiki.

B

A

Right cool yeah.

B

It's well it's only summer, and now you can start seeing exactly the Shamir secretin is now we take this. We can put this as an input to dish.

A

B

Then we have the arcade.

B

A

Just put it off here.

B

A

You get like be like right, like b1, b2, b3, b4, yeah,.

B

A

Then you just multiply them and you get.

B

C

B

Yeah, that's! This is pretty much how that works extremely.

B

B

A

Mean we got this danger where we can actually Cornelius before we couldn't.

A

Eat to get together pretty much and Doozers.

B

A

Yeah, anyway, you can restore both.

B

A

You have a prayer here.

B

Yeah I just did this wrong. I'm sorry, I.

A

Anyway, like if you have a privet, you can get deeper if you got deeper, if you can get a.

B

A

Can send it back.

B

A

B

Creates a weird little thing: there, obviously something we don't want either.

B

Yeah, it's bi-directional and it's.

A

B

A

I mean at this point like if you're doing this, you may as well just create a new key that both of you know and.

B

We have ways to securely store these keys, because you don't want to trust us a would you trust this.

A

So you also mentioned when so, let's say: Alice sends to Bob, and you know puts our keys here.

A

So yeah, it's gonna suffer Network and then at the same time now, as opposed to send to charlie the same data, said.

B

A

So she's still it's a new new.

B

A

Policy new encryption, you everything so there's no like.

B

A

A

Like, let's say as a messages might be a fast rate, so for Bob she put the CA right, yeah.

B

She she can send both.

B

A

This is a rekey a to be Rick a to see.

B

That's how it works. It's very scalable, so yeah.

A

B

Actually, at once and.

A

Then, when so, what happens when they revoke access parent, that's kind of a question because, like let's say this data is being updated every day.

B

A

B

A still encrypted or the same here right, yeah.

A

B

Need even exactly.

A

But then, when you win the revoke access from one as a parties.

B

A

But then I mean Charlie.

B

Stoddart Charlie.

A

Still has access to the new data and Bob has only access to all data very much well.

B

Not the keys have changed here.

B

A

Key did not change.

B

A

B

um He can only read it so this is so this yeah.

A

It's like it's everyday dumping,.

B

B

This case Bob has to perform this yeah. So if Alice revokes access to Bob yeah.

B

A

Exactly so then like to break into this, you need to lose.

A

B

A

B

So misuse resistant and so easy yeah I, don't take a look at our libraries before and we literally call our stuff, Alice and Bob. You know Ursula. We have these names that are so people know exactly what they don't.

A

B

To worry about, if they want to, they absolutely can, but you know they don't need to worry about these kinds of things that way they can always I'm a bomb.

B

Sometimes Alison is.

A

I've get some inception right. There.

B

A

Very nice: oh yeah, I like it again.

B

Very simple photography: it's probably not it's like what is the problem, more simplistic.

A

Yeah just sure so when, when I'm recording two new keys, let's say I'm an Alice in this case, I'm I created this new key three key for Bob.

A

Do I do this on chain when I already just sent it to them and close.

B

A

Just like that, you just send it grand transaction saying that.

B

You did it right, so all smart mm-hmm.

C

B

Has a list this is like.

A

Yeah, it's like everybody, who's take right.

B

A

I call those toke yeah.

B

B

The output she'll get like.

A

B

A

Just a dresser sir, like what will? How do you identify.

B

Okay, but we have you.

A

Have routing table.

B

A

Down the answer.

B

B

A

B

B

A

Cool, so Alice does need to run.

B

So yeah building different ways of doing that. Eventually, we'd like to be able to do just one group, yeah.

A

Exactly that's so.

B

A

In the front end yeah, just like it loads a little.

B

Bit something ways believe: is this: the security and safety of our users with a business resistance part we're so desperate, like I want to make yes, we know you want to accept JavaScript. We know you want a Giri encryption, keys and JavaScript, but it's we don't like theirs.

B

B

Just launched last night.

B

A

B

A

Time next episode.

B

A

Everybody stay tuned for next episodes.