Attendees of a community work group recently set themselves the goal of improving basic transaction privacy in Bitcoin, the aim being to define a way to defend against the most common heuristic used by blockchain analysis companies.

We are excited to announce that Liquid Network members have started the later phases of their integration efforts, and are working towards finalizing Liquid’s live launch. Liquid’s multi-asset settlement network links together cryptocurrency exchanges, brokers, and institutions around the world, enabling the rapid, confidential, and secure transfer of digital assets between participants. In readiness for this, Blockstream will provide a set of tools to Liquid members to assist with their integration and testing efforts. The first tool released will be the Liquid Block Explorer: a website that enables Liquid members to visually examine Liquid’s blockchain data, allowing them to integrate Liquid into existing systems.

Version 2: Cryptocurrency Data Feed

by Ben Richman

We are excited to announce the Version 2 launch of the Cryptocurrency Data Feed, a partnership between Intercontinental Exchange (ICE) and Blockstream. The feed provides traders best in class real-time and historical cryptocurrency data from a strong and growing list of exchange partners worldwide.

Introducing Issued Assets on Liquid

by Mike Schmidt

Liquid’s Issued Assets feature was on display at Consensus 2018. Issued Assets (IA) allow Liquid users to create their own token asset on the Liquid sidechain. These assets can represent existing financial instruments like tokenized fiat, crypto assets, attested assets (e.g. gold coins), or completely new assets. Users transact privately with Confidential Assets which hide both the amount and asset type in a transaction from outside parties.

Announcing c-lightning 0.6

by Christian Decker, Ph.D. Rusty Russell

The long wait is over: we are excited to announce the 0.6 release of c-lightning. This release is an important milestone for the project, being the first fully specification compliant release. The 0.6 release of c-lightning is a full rewrite of the previous implementation, migrating away from the previous protocol used while designing the specification, and switching to a modular and extensible architecture, to better adapt to your needs and your infrastructure.

One of the core innovations that enabled Lightning was an off-chain update mechanism to renegotiate a new state and ensure that the old state can not be settled on-chain. Today, we're excited to release our latest research paper on a new, simplified, update mechanism for layer 2 protocols, called eltoo

Blockchain is complex and blocks can be hard to find, but fear not, the team at Blockstream is always working hard to research new techniques for finding blocks and keeping them flowing!

GreenAddress has recently announced a new procedure for enabling access to users’ wallets if they had lost the ability to authenticate with their second factor authentication method. Eligible users include those that have their private mnemonic passphrase available, but do not have access to their second factor authentication method.

Blockstream’s week of LApps introduced seven new exciting Lightning Apps to the world. Here’s a look at the whole set, so you can find the one most appropriate for your use case.

Day six of our week of LApps at Blockstream sees the release of ifpaytt. This new LApp is a companion to the versatile paypercall application, but it allows non-programmers to create Lightning-powered services using the IFTTT methodology.

Today is the fifth day of our week of LApps and Blockstream is excited to announce the simple point-of-sale solution called nanopos. With nanopos, vendors can sell physical items in-person and accept Lightning payments instantly via a simple graphical display that is easily configurable by sellers.

Today is the fourth day of our week of LApps and we are excited to announce Paypercall, a new Lightning Network payments framework that allows developers to create Lightning-powered successors to current services, and new next-generation applications and services.

Day three of our week of LApps brings us to one of the most desired use-cases for Lightning Network payments: Tipping! With Nanotip, Bitcoin users can tip atomic amounts of bitcoin to anyone on the Lightning Network instantly.

On day two of the week of LApps, we are excited to announce our second Lightning-powered application! Lightning Publisher for WordPress is a plug-in that enables content creators, businesses, or anyone with a WordPress website to accept bitcoin payments for their content instantly via the Lightning Network.

Welcome to the week of LApps! Blockstream is introducing seven new Lightning apps (LApps), one per day, over the course of the next week. The first LApp is FileBazaar, an app that enables Lightning micropayments for creators who are producing digital files like photos, videos, or documents.

Liquid Release Candidate Network is Ready To Go

by Allen Piscitello

Blockstream launched the Liquid Release Candidate Network for participating Liquid exchanges. This new network marks the conclusion of Liquid Beta, and we are on the way to a production release in May 2018.

Smart Signatures - BPASE '18

by Blockstream

Christopher Allen’s talk at the recent Blockchain Protocol Analysis and Security Engineering (BPASE) 2018 conference overviewed the topic of smart signatures. He detailed the language requirements for smarter digital signatures and discussed many current experiments, including Blockstream’s own Simplicity. A video of the seminar is now available.

Bulletproofs: Faster Rangeproofs and Much More

by Andrew Poelstra

Bulletproofs are a new efficient form of zero knowledge proof. Their primary application is to replace the rangeproofs in Confidential Transactions with much smaller and more quickly-verified proofs, but they can also be used to prove arbitrary statements about committed data and secret keys. We explore their history, performance, and applications.

Pieter Wuille also spoke at the Blockchain Protocol Analysis and Security Engineering (BPASE) 2018 conference. He talked about advances for using Schnorr Signatures in Bitcoin, discussing the challenges and highlighting the advantages of this new signature scheme for Bitcoin.

Russell O’Connor spoke at the recent Blockchain Protocol Analysis and Security Engineering (BPASE) 2018 conference on the new smart contract language, Simplicity. He discussed how it overcomes the dangers of some existing languages and explained its denotational and operational semantics. A video of the seminar is now available.

Key Aggregation for Schnorr Signatures

by Pieter Wuille, Ph.D.

Last Monday we published a paper that introduces MuSig, a multi-signature scheme based on Schnorr signatures. This post will dive into its construction and a few of its applications to Bitcoin.

Lightning Charge Powers Developers & Blockstream Store

by Christian Decker, Ph.D. Rusty Russell

Lightning improves Bitcoin with lower fees, faster transactions, and better decentralization. Lightning Charge improves Blockstream’s c-lightning implementation with better accessibility for web developers. And we’ve introduced Blockstream Store to bring Lightning to life with real-world functionality, providing a way for you to test Lightning and become a part of the micropayment revolution.

Lightning Spec Electrifies Bitcoin with Release Candidate

by Christian Decker, Ph.D. Rusty Russell

Blockstream is proud to contribute as one of the implementers of the Lightning Network protocol and to take part in the joint announcement of an exciting milestone: the first release candidate of version 1.0 of the Lightning protocol specification.

Simplicity Itself for Blockchains

by Blockstream

Introducing Simplicity, a new functional programming language for smart contracts that broadens traditional capabilities with expanded functionality, improved safety, and integrated MASTs.

The Status of SegWit at Blockstream

by Blockstream

SegWit went live several weeks ago. In this post you’ll find a status update on a few of Blockstream’s projects and their support of SegWit.

Andrew Poelstra is working on three different approaches to privacy on the blockchain, each one with its own advantages. Hear him touch on Confidential Transactions, MimbleWimble and Scriptless Scripts at the Consensus 2017 blockchain event.

Announcing Blockstream Satellite

by Adam Back, Ph.D.

Technology has transformed industry after industry, and now it’s revolutionizing money and how people save and transact with each other. In less than a decade, Bitcoin has gained impressive adoption and is now at the center of innovation, leading the charge to define the future of money. To accelerate this future, Blockstream is today pleased to announce Blockstream Satellite – one more step in the journey towards everyone on the planet being able to participate in Bitcoin.

7 Common Myths About SegWit, Debunked

by Blockstream

The internet brings us many wonderful things such as new business models, new-found access to information, and new technologies like Bitcoin. It’s also a place where misunderstandings can lead to misquotes, misconceptions can take on lives of their own, and the facts can get lost on the information superhighway. In this post, we debunk some of the common myths that we’ve read about SegWit.

Learn how the advanced privacy and confidentiality capabilities with Confidential Transactions and Confidential Assets unlock the potential for blockchains in business applications.

Demonstration of Liquid Beta

by Ben Gorlick Ben Teitelbaum

This is a demonstration of Blockstream Liquid, showing how bitcoin transactions can be settled on a sidechain within seconds and with full confidentiality.

Liquid Beta Program Update

by Johnny Dilley Alex Fowler Ben Gorlick

We're delighted to share an update on Liquid, the world’s first federated sidechain that enables rapid, confidential, and secure bitcoin transfers.

Blockstream Releases Confidential Assets

by Andrew Poelstra

With Confidential Assets you can extend confidentiality to multiple asset types while obscuring which ones are in use in specific transactions.

An Update to the Elements Project

by Gregory Sanders

Since our release of Elements Alpha, we have been hard at work making the codebase production-ready for live, federated-sidechains such as the Liquid network. This post announces a number of improvements now available to developers.

Strong Federations, Foundation of Liquid, Whitepaper Released

by Johnny Dilley Jonathan Wilkins Marta Piekarska, Ph.D.

In our second white paper on sidechains, we discuss the concept of Strong Federations, or a federated blockchain system that facilitates movement of any asset among disparate markets without requiring centralized trust. Strong Federations provide security and confidentiality advantages with support for transactions where asset types and amounts are opaque while preserving the public verifiability inherent to Bitcoin. The white paper was published on arXiv, an academic e-print service.

Covenants in Elements Alpha

by Russell O'Connor, Ph.D.

This post will describe how covenants can be implemented with a small extension to the Bitcoin script language that already exists in the Elements Alpha sidechain.

Over a dozen representatives from companies leading work on Lightning systems met in Milan last week to establish a shared scope and specification for protocol compatibility.

"Adam has extensive practical experience building teams and shipping products as shown by his track record at organizations large and small, such as Microsoft, PI, EMC, and VMware," said Paul Maritz, Chairman, Pivotal, and former CEO of VMware

Today we are excited to announce some important steps we are taking on the patent front, why these defensive steps are necessary, and our hope that others will see merit in our approach and follow our lead.

We are proud to welcome Christopher Allen to Blockstream. He will be working with us on a number of strategic initiatives, including the company’s participation in the Hyperledger cross-industry collaboration, as well as future technical efforts with international standards organizations such as W3C, IETF, and Oasis.

Blockstream is off to a strong start this year with a number of new customer engagements, our announcement of a strategic partnership with PwC, and today being able to share the news of our second round of financing. I'm excited to announce that we raised $55 million in Series A funding to further enhance our sidechain technology, expand our operations globally, and support new industry partnerships, bringing our total investments in the company to $76 million.

Blockstream is pleased to announce today a strategic partnership with PwC to bring blockchain technology and services to companies around the world. The rapid pace of innovation in cryptocurrencies, distributed ledgers, and smart contract technology is driving organizations to transform their operations. PwC exemplifies the type of partner that will help us deliver the promise of this cutting edge technology.

Liquid Recap and FAQ

by Johnny Dilley

For a young company, nothing is more exciting and vital than announcing the first product. That's why it was so rewarding for us to be able to include some of our initial customers in the Liquid announcement, which helped us add a real-world dimension to our work. We also greatly appreciated the discussion that followed. We all benefit from and share in the learning process as we advance the state of Bitcoin.

Blockstream, in collaboration with an initial set of launch partners, is excited to announce Liquid, our first production sidechain. Liquid will improve capital efficiency and market liquidity by facilitating rapid and secure transfers between accounts held at any participating exchange or brokerage.

Tree Signatures

by Pieter Wuille, Ph.D.

After the release of Alpha we realized that its script language, thanks to the addition of OP_CAT, enables a simple form of Merkle tree verification. Therefore, we can now emulate a subset of MAST without any changes to the consensus rules. All we need to do is use the script language in a way that wasn’t anticipated. As you will see in the next sections, this enables some very large multisig[2] constructions with very low cost (in terms of opcodes executed and size on the chain).

Today we joined other leading California bitcoin companies in submitting a letter (link to PDF) to the California State Senate on pending digital currency legislation, AB 1326. The letter expresses our desire for California to set pro-technology policy for digital currency, and was sent from us together with Bitgo, Bitnet, Chain, Gem, Mirror, and Xapo.

We’re excited to announce the release of Sidechain Elements. Sidechains extend Bitcoin functionality through interoperable blockchain networks and today’s open source release includes an experimental sidechain that has a number of new working capabilities. With the release of Sidechain Elements, Blockstream is moving this effort into the community. We’re inviting developers to work with us, to test and use the code for their projects, and to share their proposals and code for additional capabilities. Sidechains are decentralized, peer-to-peer networks that provide useful security, risk, and performance enhancements for global systems of value exchange that don’t need intermediaries, central banks or other third parties. They are distributed ledgers that are interoperable with each other and with Bitcoin, leveraging the most secure blockchain and code infrastructure in an additive way. Sidechains enable innovators to safely develop new applications without jeopardizing Bitcoin’s core code and putting billions of dollars worth of digital currency

Blocksteam is proud to welcome three new people to our team, expanding our globally-decentralized crew from North America and Europe to now include Australia! Rusty Russell, Core Tech Engineer Rusty is a well-known Linux kernel maintainer, renowned for his foundational work on modules and iptables. After 14 years as a senior developer at IBM, he took a six-month sabbatical to work on cryptocurrencies. It was his top-notch work and writings during this period that brought him to our attention. Rusty has worked on a plethora of low-level code over the years, spoken at dozens of conferences around the world and also founded the first Australian Linux conference. He continues to maintain some Linux kernel parts as a hobby, while devoting most of his time to exploring the emerging frontier of Bitcoin development. On Bitcoin and Blockstream, Rusty notes: “I was drawn to Linux by a group of passionate developers, and

Bitcoin Core developer and Blockstream co-founder Gregory Maxwell discusses his recent work on privacy and the future of multi-signature technology at a recent San Francisco Bitcoin Devs Meetup. Maxwell explains important aspects of bringing multisig transactions to the blockchain. In the second half of the presentation he defines what effectual cryptography can look like and illustrates how developers can help create more reliable new technologies with it.

Today we joined with over sixty thought leaders, investors and companies calling on the New York Department of Financial Services to create a safe harbor under its proposed BitLicense rule. We’re excited about the recent announcements for blockchain businesses out of New York. They demonstrate an expanding recognition of the enormous potential of blockchain technology. However, as the leading technology company developing open source protocols for virtual currency and blockchain businesses, we believe it’s misguided to expect early stage companies to adhere to licensing requirements that are similar to those of large financial institutions. The untapped potential of blockchain technology is almost entirely being pioneered by startups and early stage players. These companies are several years ahead of Wall Street. Imposing significant costs and bureaucracy on early adopters will stifle innovation at a time when it’s needed most, if the not-too-distant history of the financial markets is to be avoided.

We’re proud to welcome three new members to Blockstream’s team, as well as announce the creation of the company’s first job board with several technical and non-technical openings. Glenn Willen, Core Tech Engineer Originally from Los Angeles, Glenn got a Bachelor of Science in Computer Science from Carnegie Mellon University in 2007, followed by a four-year stint at Google as a Software Engineer and a Site Reliability Engineer. About working with Blockstream, Glenn says, “I’ve been following Bitcoin since I read about it on Slashdot in early 2011. I love truly decentralized systems, like the ones that have survived from the early days of the Internet, chief among them email and the web. I hope to see Bitcoin take its place among them someday.” James Murdock, Vice President Corporate Development & General Counsel James holds extensive legal and business strategy experience ranging from IP, cyberlaw, M&A and global partnerships. He was previously Senior

In a recent episode the Epicenter Bitcoin podcast, posted on February 3, 2015, Adam Back and Gregory Maxwell discuss the motivation behind sidechains, the concept of digital scarcity, concerns about the security of sidechains and the different stages of sidechains from federated pegs to merged mining to block extension.Video courtesy of Epicenter, hosted by Brian Fabian Crain & Sébastien Couture

“The Bitcoin Policy Prescription: Will Policymakers Get It Right (Again) Or Will Fear Stifle Innovation?” That was the question posed to a panel at this year’s State of the Net conference, held on January 27, 2015 in Washington DC. Along with Blockstream Co-Founder Alex Fowler, other panelists included: Eli Dourado, Research Fellow and Director of the Technology Policy Program, Mercatus Center at George Mason University; Vanessa Kargenian, Supervisory Development Associate, Federal Reserve Bank of New York; and Chip Poncy, Co-Founder, Financial Integrity Network. The panel was moderated by Jerry Brito, Executive Director of Coincenter.  Video courtesy of State of the Net, hosted by the Internet Education Foundation

Reprint: “The Future of the Bitcoin Ecosystem and ‘Trustless Trust’ – Why I Invested in Blockstream,” by Reid Hoffman, LinkedIn’s Pulse, November 17, 2014 Bitcoin is often characterized in the media as a volatile virtual commodity that can optimize speculation even more efficiently than gold, securitized subprime mortgages, or tulips. That’s not how I think about it. For me, Bitcoin is a transformative addition to Internet communication protocols that will create new networks of trust, fuel massive economic ecosystems, and create enduring long-term value. Beyond arguments over whether Bitcoin functions more like a commodity or a currency is the fact that it introduces the blockchain, a distributed ledger that resides on tens of thousands of servers around the world. Every time one party exchanges some amount of bitcoins with another party, this transaction is checked against this public and permanent record of every Bitcoin exchange that has ever happened. The

Blockstream closes $21M seed round

by Austin Hill

“Can’t be evil.” That was the first thing Adam Back and I wrote on a whiteboard at the start of 2014. I had flown out to Malta to spend a week with Adam to map out a vision for an ecosystem and a future we wanted to see built. In the late 90’s I had the pleasure to recruit Adam after reading his Hashcash whitepaper to join the team of cryptographers we had at Zero-Knowledge Systems. Zero-Knowledge Systems was a company I co-founded with my father and brother to commercialize several cypherpunk privacy-enhancing technologies, including anonymous encrypted networking and Dr. Stefan Brands’ pioneering protocol for e-cash (still the most-flexible and powerful of the central-server protocols developed to date). While we had some amazing successes, many of which live on today, we were too early to see wide scale market acceptance of our e-cash work at that time. Fast forward to December 2013 the roles

As someone with some community visibility, I make this commitment to the community: Blockstream will be a robust champion of Bitcoin’s ethos, supporting values of decentralisation, end-to-end security, user control, user values and open, permissionless innovation. To me, and my Blockstream co-founders, these are more than mere words. They represent deeply rooted beliefs and a culmination of decades of involvement in the technology community and related professional work. The technical team and I are making a choice by founding this company to work towards extending bitcoin. This choice is a direct reflection of the primacy of our commitment to bitcoin. Blockstream arose from a firm belief that sidechains are the most important and pressing technical work ahead for Bitcoin to reach its full potential as a programmable money and asset internetwork. The seeds of Blockstream originated from the values shared by the cypherpunk community. It was through this network that

Since releasing our paper, “Enabling Blockchain Innovations with Pegged Sidechains,” we've been pleased with the overwhelmingly positive response from the Bitcoin community and also the enthusiasm for the kind of innovation sidechains can enable. We received close to 10,000 downloads of the paper, saw a number of excellent blog posts and critiques on sidechains, and over 3,000 people logged in for a Reddit AMA with us to discuss the paper and Blockstream. However, we noticed a handful of comments that reflected some misconceptions and a few concerns regarding our integration into the Bitcoin ecosystem that we thought it would be helpful for us to address now, while the discussion is still ongoing. I've pulled them together into six questions and worked with the other authors to provide responses.

Why We Founded Blockstream

by Blockstream

We are long-time Bitcoin protocol developers who are convinced that finding an architecturally sound and permissionless way to extend Bitcoin is essential for cryptocurrency to reach its full potential.