David chaum crypto

The resulting blind signature can be publicly verified against the original, unblinded message in the manner of a regular digital signature. In , he with Hans van Antwerpen introduced undeniable signatures. Since signers may refuse to participate in the verification process, signatures are considered valid unless a signer specifically uses a disavowal protocol to prove that a given signature was not authentic. In , he with Eugene van Heyst introduced group signatures , which allow a member of a group to anonymously sign a message on behalf of the entire group.

In , Chaum proposed the idea of an anonymous communication network in a paper. Once the server has a batch of messages, it will reorder and obfuscate the messages so that only this server knows which message came from which sender. The batch is then forwarded to another server who does the same process. Eventually, the messages reach the final server where they are fully decrypted and delivered to the recipient.

A mechanism to allow return messages is also proposed. Mix networks are the basis of some remailers and are the conceptual ancestor to modern anonymous web browsing tools like Tor based on onion routing. Chaum has advocated that every router be made, effectively, a Tor node. In , Chaum introduced a different type of anonymous communication system called a DC-Net, which is a solution to his proposed Dining Cryptographers Problem. Chaum has made numerous contributions to secure voting systems, including the first proposal of a system that is end-to-end verifiable.

This proposal, made in , [27] was given as an application of mix networks. In this system, the individual ballots of voters were kept private which anyone could verify that the tally was counted correctly. This, and other early cryptographic voting systems, assumed that voters could reliably compute values with their personal computers. In , [ citation needed ] Chaum introduced SureVote which allowed voters to cast a ballot from an untrustworthy voting system, [31] proposing a process now called "code voting" and used in remote voting systems like Remotegrity and DEMOS.

In , Chaum introduced the first in-person voting system in which voters cast ballots electronically at a polling station and cryptographically verify that the DRE did not modify their vote or even learn what it was. In , Chaum proposed Random Sample Elections. In , Chaum proposed a mechanism for splitting a key into partial keys, a predecessor to secret sharing. In , Chaum proposed the original anonymous credential system, [19] which is sometimes also referred to as a pseudonym system.

Chaum contributed to an important commitment scheme which is often attributed to Pedersen. In fact, Pedersen, in his paper, [46] cites a rump session talk on an unpublished paper by Jurjen Bos and Chaum for the scheme. It appeared even earlier in a paper by Chaum, Damgard, and Jeroen van de Graaf. In with Stefan Brands, Chaum introduced the concept of a distance-bounding protocol. From Wikipedia, the free encyclopedia. American computer scientist and cryptographer.

Inventor Cryptographer. S2CID Wired Magazine. Bloomberg News. May 27, Dutton Adult. ISBN Microsoft Research; For the paper, see Chaum, David Communications of the ACM. Penguin Books. MIT Press. ISBN X. Archived from the original on Retrieved Retrieved June 17, Retrieved May 16, And I think that will really demonstrate it will really shine there. Why do you feel that metadata is so critical to the privacy and sovereignty and vision of individuals and because a lot of times people talk about their privacy and I think they [only] consider the message.

How would you effectively communicate that to someone that beyond the message that all the extra inferences that we can make them up, that metadata are as equally weaponizable, I guess,. And this is a fundamental and sort of irreversible phenomenon. Whereas if you look at the non-democratic parts of the world, you see that the same manipulation of media… and so on, is underway and diffusing any real hope of kind of a rise of public sentiment.

Just look at the way China has manipulated mainland opinion related to the recent events in Hong Kong. I was just reading about it. This is quite, quite stunning. Just because most of us, I mean most of us use Google and almost all of us at some point or other used to use Facebook and I mean Facebook is not such a thing anymore.

And your privacy and your data. David : First of all. But in any event, now that the Elixxir platform is starting to become available, I really have no excuse not to use something that actually does protect privacy and shred the metadata and so forth. Sebastien : Okay. Gmail of this sort of thing? And sometimes that means making compromises in terms of my own personal protection, where I better put the energy into, try to come up with things that really can address the key issues and trying to find a way to get them out that seems attractive too to the widest possible audience.

Sebastien : I get, I mean, we all have to make compromises at some point. I use signal with my family, but it takes a lot of time, right? Sebastien : One of the things that I found challenging a was getting friends and family to use the systems that I was using and that I thought would protect my privacy. And so the challenge was getting people to use that.

How have you effectively communicated that with, your friends and colleagues for them to start using those systems? I would say people that are not so concerned about the privacy like we are? David : Well the history of social media, even though at any moment in time it looks the most dominant systems are never going to be displaced, the history proves that every few years there is the mass migration to the next best thing.

And this has happened, more than a half dozen times and I believe that now the public has become quite disenchanted with the tech powers that be, they feel betrayed by the fact that they, their data has been misused without their permission of course and with such devastating consequences for faith in democracy, and so on. They are companies. So we have this ability to dramatically change the whole landscape by creating an un-permissioned chain which offers these kinds of capabilities to the public for free.

So I think that with the thought leaders and people yourselves and, and your listeners on this podcast and so forth, this can provide the sort of initial critical mass that will then because of the network effect lead to a mass migration and that can be a tremendously helpful thing for the future of the free world.

Friederike : Yeah. I mean basically you get these major consensus narrative shifts. And you get you get this mass migration to a new thing and I think you may be completely right in that. That recently a movie on Netflix came out, a documentary called the great hack. Have you seen it? Friederike : Yes. I want to go into your solution for this problem a little bit later on in the show.

Your first company was DigiCash. Can you tell us when you got the idea for DigiCash and, how it actually worked. David : Sure. Well, in I published a little paper on blind signature based payments. You should ask, I actually invented something in that could do that. David : And they said, Oh, well, really? Well, I mean, would it be fast enough?

And I said, Oh yeah, I think we could do it. And they said, Oh really? I said, yeah, well say what if, if we can do it in two weeks, will you give us a contract to build it? We can prove to you that we could do it in two weeks. And they said, sure. So I got a bunch of students and we wired up this house, and it was a crash project. And in about 10 days actually built a little hardware gizmo that used to say, kind of micro controllers that a smart card of 60 to five.

And, we demonstrated that we could make these blind signature payments in a special way, at that kind of speed. And so they gave us the contract and we had to build that. And so I hired the students and we started building it. And this was a done on the same campus as my research group, but it was in a separate facility and eventually as the web started to emerge, I moved over to actually run the company. Sebastien : So from there this was kind of the inception of DigiCash and so DigiCash was used to manage this toll payment system.

David : Well, in I gave one of two keynotes and the first keynote at the worldwide web conference. It was the first worldwide web conference in Geneva. And what I did of this in those days was, we use the web browser to make the slide presentations right. And this was projected by a huge projector. And I made the [ first ecash payment from Geneva to Amsterdam, and launched this idea that number could be worth money, so-called digital bearer instrument.

And launched the DigiCash company. And this was picked up by all kinds of media around the world. Within a couple of days, there was a lot of interest in the idea that a number could be worth money, a digital bear instrument. And so we were very much in the spotlight and we kind of started with the first thing which was called cyberbucks. And this is a digital currency as currently understood but different than a few ways. So one commonality is that it had a limited amount of the currency that was going to ever be issued.

So that was an interesting thing, a good innovation. The another thing was that of course all the transactions conducted online, it differs technically from current blockchain which have, arguably, zero privacy, right? Whereas DigiCash use of the blind signature concept you mentioned earlier that has a really nice special kind of privacy with some metric called one way privacy or payer anonymity , which is essentially that only the person who forms the digital coin, initially at random, should be the user can recognize it later.

But that digital coin is unlinked bubble to the withdrawal process where it was originally signed. So what it amounts to is that as the payer, you can always irrefutably prove who received the money from you, but they cannot find out who you are.

The three types, extortion, black markets and bribery. And if you think about it, such a one way privacy it makes the money unsuitable for any criminal use. Because you know what kidnapper would accept payment by check or, or what politician would accept the bribe by, wire transfer or in a black market.

So it was quite unique. And so what this means is that each coin has a phase one of a fixed set of denominations. On current blockchain, where that is in effect a digital check system where each transfer has a potentially unique amount, which links it horizontally from account to account from, well I need a wallet ID with, with DigiCash each 1 cent or 2 cent 4 cent eights that we use. So that because of the standardization of and that sort of breaking the payments up in, into just paper money and coins today, metal coins.

So another difference of the DigiCash, technology. Sebastien : So who are the users of the DigiCash? Was it mostly for online purchases or were there are certain use cases that you were starting to kind of pick up on when, when, when it started getting traction? David : Well, so those initial payments were part of the Cyberbucks and you could call today in airdrop.

But our condition on that was that you have to create a shop, an online web based shop that accepts cyber bucks for something. And if you go to chaum. You can see all the press releases in somebody, you can actually see the icons of a lot of the shops that, were up issuing, selling things for ecash and that participate in the CyberBucks launch of ecash bots. Then we also subsequently licensed banks around the world to issue ecash in their national currency at the time, as well as for internal use.

So the securities, they use it internally, but we had issuers in most, most continents. We had Australian dollars, we had US dollars. In those days it was pre Euro, so this would be at the Deutschmark and then a number of other licensees in Scandinavia and so forth. So actually Deutsche bank in those days was the biggest bank in, in Europe, indisputably. And they were like toughest customer. They had a data center that was an old bunker underground and they wanted every kind of industrial audit back up, role in every kind of protection and everything.

And so we had to build all that stuff for them and they, they deployed it and there were shops that accepted payments, why he cash Deutschmarks and so they were very enthusiastic about it. But the web has grown very, very rapidly in those days. And so there was just a, it was very difficult to deploy. It was somewhat of a labor of love to install. And he cashed client in your computer in those days and keep it up to date and eh, and so forth.

So it was a, the interesting times. Sebastien : I remember back in my mid teens in the late nineties, wanting to buy some, I wanted, I wanted to order an SSH server or something, and the only way to do it was to pay online. And, so having something like Digicash back then would have been very useful. David : A handful of banks around the world which issued ecash. And what that technically meant was that if you had an account at their bank, then you could withdraw money from your account into ecash, just you could visit an ATM machine and withdrawn into paper money.

So you could load up your ecash wallet from your bank account and then you could spend that money. But it was in the form of these binary denominated digital bearer instruments that all of our payments were privacy protected in that way, with blind-signatures then you, you could spend that at any of the shops that would except it. Sebastien : It strikes me that this is kind of similar to, so some of the assets back stable coins that we see in the space now and in some way it put setting aside all the privacy issues, etc.

But in some way it is a little bit similar to what Facebook has proposed in Libra in that cryptocurrency. Would you not say so? David : Well way I frame it is that we issued a free standing digital currency cyberbucks. And we had a way to get it except that a lot of merchants and we gave it away. So we were trying to create our own currency with a bounded cap. And in parallel with that we allowed others to issue their own versions of it and we help them do that.

And those others all turned out to be banks or I think there were also the, Nora was a research organization and I think that the Sweden pulse license it so people would want to use it beyond other than bags. But we try to make it available to anyone who wanted to use it.

But in those days we had to help them do it. And so we wanted this stuff to be come the digital currency, but there was such a rapid growth, that hesitation and then lurch forward of growth and was not anywhere near as convenient as credit cards once that became a viable option.

Can I do that with any bank or just my bank? Or how does it work? So there was a bank called Twain bank in the U S they issued you a Starz, but they would also accept other currencies I and convert. And that was w was provided by a bank that was actually part of the eco system. David : Well, DigiCash did make money and I mean, we did the cyber box thing for free and we hope to really foster the creation of an alternative currency based on, pretty idealistic vision for that.

But we also, licensed banks and organizations as I mentioned. And, and for that, they paid us for the right to do it and paid us to help them. And we had S I think a the sound and sustainable business model. But then as the web really started to take off, we saw, I decided that this technology was too important to not be given a chance to really rise with the tide.

Like, you mentioned business model in your question, but I decided that we should really just go for, try to make the world a better place and try to rise with the tide. So we took in fair amount of money under terms that assume that those people who put the money in really had the same concern about changing the world as us.

But in the end that in proved to be the case. What are you trying to achieve with this new project? And that also allows for the integration of dApps and in that way positions itself as a a full alternative to the we chat or a Facebook with labor or some of these other offerings. And, and I believe a very attractive alternative. And with the network effects we can expect perhaps a very rapid transition. Friederike : That sounds super exciting.

Are absolutely get free ethereum wallet phrase

Currently, the commonly used methods for ensuring the integrity of a blockchain are the energy-hungry Proof of Work PoW and the newer Proof of Stake PoS. Along with adding security, the team of nodes do most of the computation before the transaction gets to them. Once it does, it can be processed much faster than on traditional blockchains.

What about the scalability angle? In an interview with Blockchain News , Chaum explained that just eight nodes can make up a team. As the network grows, the protocol can use additional teams without a significant slowdown. The result is a blockchain scalable enough for a global transaction platform, as the announcement claims. One of the aims of the new blockchain is to support and complement Elixxir.

By metadata, Chaum is referring to the sort of data that Facebook gleans about users. Or the trail left by Bitcoin that makes transactions very traceable. The Elixxir project aimed to give messages and transactions complete privacy. Elixxir emerged in September of last year to tackle this privacy issue as a combined messaging and payments platform.

This keeps the metadata of individual messages private and means that messages are indistinguishable from transactions. Praxxis utilizes Elixxir to enable private transactions on its blockchain. David Chaum is credited with creating the first digital cash, known as e-Cash. While he also came up with the idea in the s, it came to life during the dotcom boom of the late nineties. He had recently proposed a system which was very close to a blockchain — he only missed the decentralized part.

This meant that e-Cash, now thought of as a precursor to modern digital currencies, had to be managed by a centralized body like a bank. It turns out he had been working out of the public eye on data privacy and the pre-computation angle of his nodes team concept. All that work has finally emerged in the form of Elixxir and Praxxis, which he hopes will be a realization of truly peer-to-peer electronic cash.

Combining messaging and blockchain-based payments itself is not a new idea, Telegram, for instance, is big competition, plus Facebook has now joined the fray with Libra. Invented what remain the key privacy-technologies—untraceable communication, digital cash, and reputation credentials. Invented and as DigiCash CEO saw through to global deployment the first digital bearer instrument and first privacy-protecting electronic payments.

Named the area and led a research effort that proved the fundamental theorems in the three main models and unilaterally in a combined model. Invented and led successful implementation and deployment of breakthrough election technology—including software, hardware, special printing and inks—for the municipal elections of Takoma Park Maryland in and again by invitation in All styles and presecriptions of eyeglasses can be upgraded to overlay, anywhere you can see through them, digital imagery that is of unbeatable quality.

Invented, founded and established feasibility of a new paradigm that digitally deconstructs images so when projected by eyewear they reconstruct on the retina with dynamic focus and resolution exceeding the limits of perception. Profile Widely recognized as the inventor of digital cash, David is currently leading Elixxir and Praxxis to provide scalable digital sovereignty. Projects Praxxis High Performance digital currency supported by a quantum-resistant blockchain.

View more View more. Elixxir Breakthrough privacy platform that enables true digital sovereignty at consumer scale. International Association for Cryptologic Research Organized one of the first conference on cryptography and used it to found and launch IACR, at a time when NSA was threatening scientific societies to halt presentation of papers on crypto It remains the scientific society of the field, sponsoring three conferences each year around the world as well as multiple workshops and a scientific journal.