A blockchain, at its very core, is a way for everyone to agree on what the current state of the world is, without having to rely on a trusted authority.
Of course, by “everyone” we don’t actually mean everyone, but instead everyone who believes in the security model. Likewise, by “the world” we also don’t actually mean the world, but rather, whatever is currently written on the blockchain’s ledger. Nevertheless, well-known blockchains such as bitcoin or ethereum both have market caps in the 100s of billions of USD, which tells us that the technology excites people.
Programmable blockchains, in particular, are exciting because their “world” is very rich. On a programmable blockchain, the “world” is basically the current memory of a computer, and so, simply by being clever about how we design the programs that run on this computer, we can use it to accomplish almost anything.
Let’s digress for a bit and classify programs into three categories:
— Those that take a public input and produce a public output
— Those that take a private input and produce a public output
— Those that take a private input and produce a private output
A programmable blockchain such Ethereum supports programs of the first kind: Everyone sees what goes into a smart contract on Ethereum, and everyone sees what comes out again. This is great for some applications (like agreeing on who bought a NFT), but clearly not sufficient for others (like performing an auction).
Several solutions have surfaced which attempt to support the remaining two types of computations. Let’s take a brief look at some of them:
Zero-knowledge proofs (ZKPs) are, in a nutshell, a way for someone to convince (i.e., prove to) someone that they know or possess something, without revealing anything about that something. One situation where this shows up, is when someone wishes to prove to someone else that they control a certain amount of tokens.
ZKPs can therefore be used for private-public and private-private computation, to a limited degree. ZKPs can only compute, well, proofs. This in particular means that the computations are limited to a binary “yes” or “no” output. Moreover, ZKPs are inherently single-user oriented, so it is not possible to perform a computation that takes multiple private inputs.
Note that a program that takes a public input, but produces a private input does not make sense. If everyone can see the program and what goes into it, then everyone can obviously see the output as well.
Another private computation technique is fully homomorphic encryption, or FHE as it is called for short. At its very basic, FHE is a way of encrypting data such that it is possible to perform computations directly on the encryption.
This immediately tells us that FHE for sure supports private input private output type computations.
However, FHE, like ZKPs, are oriented towards a single user scenario. This means that, although FHE can perform any computation (which ZKPs cannot do), they cannot perform a computation that receives private inputs from multiple users.
In contrast to the two above technologies (as well as the next one), trusted execution environments (shortened as TEEs) are a purely hardware based solution to the private computing problem we’re looking at.
A TEE is simply a piece of hardware that have been hardened in certain ways that make it hard to break into. If we believe this to be the case, then a TEE can be used to perform the private input, public/private output computations we’re interested in.
Inputs are encrypted using a key stored only on the TEE, and computations take place on the TEE after decryption. When the computation is done, the output is encrypted (or not, depending on whether the output should be public or private) and then output by the TEE. In this way.
TEEs therefore clearly support the type of single-private-input computations talked about so far. However, the situation is a bit complicated if we want to receive inputs from multiple sources. Indeed, the only way that can be possible, is to make sure the same key is stored on everyone’s TEE.
The last tech I will look at is secure multiparty computation, or MPC. This privacy tech supports both types of computations, just like FHE and ZKPs, but where it distinguishes itself is that it naturally supports private inputs from multiple sources. Indeed, there’s a reason it’s called secure multiparty computation.
This makes MPC especially suited for a blockchain because of its multi-user nature.
The above categorization leaves out a lot of details, since it talked about neither the security models that each of the technologies use, nor about their efficiency.
Each of the four technologies above operate in a particular security model, and none of the models are exactly the same. Likewise, they each have some properties that make them desirable compared to the others. (For example, FHE requires more computation, but less communication, than MPC.)
In general, MPC does seem to come out on top, and is the only technology that easily supports computations where multiple users provide inputs. MPC, by its nature, is a decentralized technology, which is probably why it works so well in a blockchain setting. That being said, an ideal world would probably use all of the technologies in a carefully created orchestration to ensure the best guarantees in terms of both security and efficiency.
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Self-sovereign identity (SSI) is an ever increasingly important concept to enable users control over their own data and let them share it with whom they want. Today, data rests in centralized databases that belong to big enterprises with little transparency into how the data is actually being used and for what purpose.
SSI turns this around and data starts with the users, actually resting at users own device at first. Then it is up to the users to choose with whom and what data they share. Additionally, privacy-preserving features, such as selective disclosure and predicates enhance the user to share data without sharing it all or just prove simple facts about the data.
There are many great tools and infrastructures that can handle SSI, and Partisia Blockchain’s MPC technology adds a new component to the stack that enables new business models, enhances privacy for the data-driven economy, and will take your project ahead of the competition. So read on if you are a builder of the US$27 billion global digital identity market that is expected to expand at a CAGR of 17.2% from 2023 to 2030.
First things first, digital identity usually revolves around three actors: issuer, holder, and verifier.
The issuer issues verifiable credentials to the holder, and the holder can then present the credentials to a verifier who can verify the content by digital signatures and Decentralized Identifiers (DIDs) that may be on a blockchain. For most digital identity use cases, DIDs and associated DID documents are the only elements that get on the blockchain. We do not take a deep dive on this in this article.
DIDs and verifiable credentials are some of the essential components that make up digital identity, especially digital identity that works with decentralized networks. DIDs are a type of address that is generated to manage digital signatures, and verifiable credentials are credentials created and issued by any issuer based on their DIDs.
To enable real SSI, the users will have to store all data themselves at first, often in digital identity wallets, and only then will the user be in full control. The data itself can be data inputs from users such as personal Identifiable Information (PII) or digital verifiable credentials issued by a third-party, e.g. KYC provider issues KYC claim as digital verifiable credential. Credentials are often issued and exchanged by an agency that establishes secure peer wise connections.
Multiparty computation (MPC) is a groundbreaking technology that allows multiple data inputs to remain private while still being computed on and only sharing the outputs. The computing itself is carried out by specially selected MPC validator nodes who each compute on secret shares of the data and privacy is guaranteed by cryptography.
Compared to ZK proofs, such as zk-SNARKs, MPC is a game changer that allows computing on any function. This takes digital identity to the next level because it is now not only possible to share data with privacy features, but also carry out decentralized computation on private data and write business logic into private and public smart contracts to orchestrate the process and rules.
As we learned before, ZK proofs are good for simple presentations about specific data, e.g. a verifiable credential issued by an employer can be used to prove to the bank that you earn more than US$80,000 a year to qualify for a loan without revealing the exact amount you earn.
Now imagine that we need to compute statistics on multiple inputs from multiple users and compare a single person’s salary to the average, all while preserving privacy. ZK proofs cannot handle general computations on multiple inputs and comparison is limited to two users presenting against each other, so another system would have to support it. This is where Partisia Blockchain’s MPC comes to save the day! MPC on Partisia Blockchain can handle multiple inputs and preserve the privacy while carrying out efficient general computation.
Even though all smart contracts and data can be private, it is often worth considering only to push the most sensitive data and operations into private computation because it is generally more expensive than public computation. This goes for all ZK technology. For instance, if you want to calculate the average salary of employees, you might consider just the salary as private inputs plus pseudonymized identity, and then do statistical calculations in the public space.
When we look at DID/SSI solutions, the business requirements of the implementation usually go past simple verification of ID. DID/SSI proof is just the first step. The real challenge is what other data do you need after the verification. Perhaps it is to verify that this person has proper credentials for accessing a system. Or another popular use case for DID is to verify a user has enough assets to pay for something without revealing their total asset holding. Another app that is looking to build on our system is trying to create a persona on-chain, which advertisers can target, without revealing personal information about the user themselves.
In all these use cases, a simple proof system becomes too expensive and slow due to the fact that each individual parameter must require a proof. When you have 10 users, maybe this is possible. But what happens when you need to scale to 1000 or 10,000 users? And proofs are not computations. It is unable to compute the various different private data for analysis.
This is where MPC can extend the functionality of DID/SSI to create multi-functional applications. Through MPC you can both prove and compute multiple parameters in a single computation and include all the additional business requirements while keeping the data private.
During the pandemic, many attempts were made to create a Covid-19 passport so citizens could prove they were either vaccinated or tested negative while preserving privacy. Zk proofs are good for this, but limited to only presenting yes/no results to a verifier without extensive physical verification such as ID cards, which would compromise SSI principles.
In collaboration with HES-SO Valais-Wallis, Partisia Blockchain developed a solution where identification is reduced to matching an individual’s face with an image of the person’s face powered by MPC in order to increase security and privacy. The Partisia Blockchain ensures trustworthy information is broadcasted to the verifier and MPC ensures that the private information about the citizen is used only for matching and kept hidden for the verifier.
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July has brought remarkable progress and achievements to Partisia Blockchain! We are thrilled to share the latest developments in our dynamic ecosystem. In July, we unveiled our Grants Program for the second half of 2023, empowering visionary builders in the blockchain space with up to 3 million $MPC tokens. These pioneering teams will have access to cutting-edge technology and infrastructure, unlocking new possibilities in decentralized applications. Our commitment to driving innovation goes beyond financial aid — we empower those who challenge the status quo. Join us as we explore the exciting developments in our ecosystem, reflect on our impactful presence at EthCC, and delve into the tech highlights that pave the way for a more robust and user-friendly Partisia Blockchain.
Partisia Blockchain Foundation was thrilled to reveal our Grants Program for the second half of 2023, offering up to 3 million $MPC tokens (valued at US$1.2 million as of today) to pioneering builders in the blockchain space. We are seeking teams determined to create unique solutions that surpass current blockchain limitations. With our support, these projects will have access to cutting-edge technology and infrastructure to bring their groundbreaking ideas to life, addressing challenges previously considered impossible on other chains. Our commitment to driving innovation extends beyond financial aid, as we commit to empower teams that stand out and revolutionize the possibilities of decentralized applications. You can check out our value proposition and read the grant guidelines to apply now!
The Partisia Blockchain team was also thrilled to participate in EthCC conference in Paris in July, where we celebrated collaboration, strengthened partnerships, and reconnected with blockchain friends. Thanks to EthCC for providing a valuable platform for us to showcase our innovative technology, enabling secure collaboration while preserving privacy through advanced Multiparty Computation (MPC). We hope to see more of you next year.
As adoption is one of the main focuses for us, we kicked off a new adoptions team creation with a meeting in Aarhus. All the adoption officers were brought together to align on our strategy and goals for this year. Some of the key areas we agreed to focus on were in metrics, (number of leads from various sources, percentage of conversion, effective marketing campaigns, etc) to understand better where we are doing well and where we need to improve on.
Talking about adoptions, we are also happy to introduce another amazing project that has signed on to build on Partisia Blockchain. Veric is a credential and asset oracle running on Harmony One and they will begin to integrate Partisia Blockchain’s privacy technology to add additional functionality to their application. By adding the privacy layer, they aim to privatize details of their assets that they are looking to use for payment.
We were also honored to participate in this year’s University of Geneva “SDG Summer School”. The focus this year was “Open Source Health Solutions” and students from across the world met during three weeks on the ground and online. We had the pleasure of coaching a group of young minds looking to solve a technological problem for a healthcare company. The innovative solution the students came up with uses MPC and blockchain technologies and could have a positive impact on women’s health.
In line with our Ecosystem Focus, we were excited to showcase SecondLane, a groundbreaking project co-founded by key players in the Web3 OTC market. Offering advanced technology and licensing expertise, SecondLane is building on Weezi empowers project teams, advisors, and investors to unlock liquidity for unvested tokens and equity, while also facilitating the discovery and trading of illiquid digital assets. Explore SecondLane’s unique features in our guest blog, and join us for an insightful Q&A discussion with Oleg Ivanov, Co-Founder of Weezi/SecondLane, to gain exclusive insights into the platform.
As we reflect on the exciting developments in July, Partisia Blockchain has been busy pushing the boundaries of our technology and infrastructure. Here are some of the key highlights from our roadmap.
With these exciting developments, we are paving the way for a more robust and user-friendly Partisia Blockchain. As we move forward, our team is eager to reveal more groundbreaking tech updates next month. Thanks again to our community and your continued support!
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