• Flyclient: Super-Light Clients for Cryptocurrencies

    Benedikt Bünz, PhD Student in the Applied Crypto Group at Stanford, will speak about Flyclient (https://eprint.iacr.org/2019/226.pdf), a super-light client for cryptocurrencies. "Abstract: To ensure the validity of transactions, cryptocurrencies such as Bitcoin and Ethereum require nodes to verify that a proof-of-work blockchain is valid. Unfortunately, this often entails downloading and verifying all transaction blocks, taking days and gigabytes of bandwidth and storage to verify the blockchain. As a result, clients with limited resources such as mobile phones cannot verify transactions independently without trusting full nodes. As a solution to this, Bitcoin and Ethereum offer light clients known simplified payment verification (SPV) clients, that can verify the chain by downloading only the block headers which have significantly-smaller size than the full blocks. Unfortunately, the storage and bandwidth of SPV clients still increase linearly with the chain length. In Ethereum, for example, an SPV client needs to download and store more than 3.6 GB of data. Recently, Kiayias et al. proposed a solution, known as the non-interactive proof of proof-of-work (NIPoPoW), that requires a light client to download and store only a polylogarithmic number of block headers. Unfortunately, NIPoPoWs suffer from several drawbacks: they are succinct only as long as no adversary influences the honest chain. Furthermore, they can only be used for proof-of-work chains that have a fixed block difficulty, which is not the case in most cryptocurrencies, including Bitcoin and Ethereum, that require adjusting block difficulty frequently according to the network hashrate. In this paper, we introduce Flyclient, a novel transaction verification protocol for light clients that is efficient both asymptotically and practically. Our protocol requires to download only a logarithmic number of block headers to synchronize and verify transactions while storing only a single block header between executions. We formally prove that Flyclient is optimal for this class of protocols. For Ethereum, our protocol achieves a proof size of only less than 500 KB. This is achieved by utilizing a simple design based on Merkle Mountain Range (MMR) commitments and a probabilistic block sampling protocol. Flyclient overcomes the limitations of NIPoPoWs and generates shorter proofs over all measured parameters. We also discuss how Flyclient can be implemented via a soft fork in Bitcoin/Ethereum."

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  • Socratic Seminar #8

    DG717

    Inspired by Bitdevs NY, this is an event for those interested in discussing and participating in the research and development of Bitcoin and related protocols. Unlike the monthly speaker event, the Socratic Seminar events are formatted to foster debate, information sharing and lively discussion. Discussion topics from a variety of sources are collated by meetup members in the weeks preceding the events. We investigate pull requests in the Bitcoin Core, lnd, grin and other relevant repositories; we study network statistics, research papers, technical blog posts and other interesting content. To complete the meeting, members present open source projects, companies, research and other relevant materials. A feedback and Q&A section follow. A newsletter is sent out the day of the event which outlines discussion topics. Archives of discussion topics and presentations can be found in the event descriptions of past meetups. The discussion portion of the event is NEVER recorded. It is recommended that you have a firm grasp of the basics of Bitcoin in order to extract the most value from our Socratic events. Please contact the organizers if you'd like to present at a future Socratic event or have a recommended topic for discussion: leishman3 at gmail. There are different requirements for presentation depending on the type of project. Reading list: https://www.sfbitcoindevs.org/socratic/2019/03/16/socratic-8.html

  • bcoin: An alternative implementation of the Bitcoin protocol written in JS

    We're excited to have Matthew Zipkin, Developer Advocate at bcoin, speak about bcoin. "bcoin is an advanced Bitcoin library that gives users direct access to the Bitcoin "full stack". It supports full, pruned, and SPV nodes, Neutrino filtering, custom indexing and endless plugin support. Developers can access individual modules to build anything from a simple webapp to a cross-chain atomic swap wallet. In this talk we'll discuss the architecture of the system, our motivations and style, and the applications our own team is building on bcoin, including an advanced multisig wallet with hardware support."

  • Socratic Seminar #7

    DG717

    Inspired by Bitdevs NY, this is an event for those interested in discussing and participating in the research and development of Bitcoin and related protocols. Unlike the monthly speaker event, the Socratic Seminar events are formatted to foster debate, information sharing and lively discussion. Discussion topics from a variety of sources are collated by meetup members in the weeks preceding the events. We investigate pull requests in the Bitcoin Core, lnd, grin and other relevant repositories; we study network statistics, research papers, technical blog posts and other interesting content. To complete the meeting, members present open source projects, companies, research and other relevant materials. A feedback and Q&A section follow. A newsletter is sent out the day of the event which outlines discussion topics. Archives of discussion topics and presentations can be found in the event descriptions of past meetups. The discussion portion of the event is NEVER recorded. It is recommended that you have a firm grasp of the basics of Bitcoin in order to extract the most value from our Socratic events. Please contact the organizers if you'd like to present at a future Socratic event or have a recommended topic for discussion: leishman3 at gmail. There are different requirements for presentation depending on the type of project.

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  • Implementing Compact Threshold MuSig Signatures

    We are excited to have Andrew Poelstra, Director of Research at Blockstream speak about MuSig! "Andrew will describe their efforts to implement threshold MuSig signatures in which all participants shard their secret keys using Verifiable Secret Sharing, and accumulate the shards they receive to construct new secret keys. He will also discuss the notion of accountability for threshold signatures, which allows third-party verifiers to determine which subset of signers produced a given signature, but which typically comes at a significant verification/storage cost. In the talk, Andrew will consider a "semi-accountable" signature scheme wherein a non-accountable signature commits to an accountable signature using sign-to-contract."

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  • Socratic Seminar #6

    DG717

    Inspired by Bitdevs NY, this is an event for those interested in discussing and participating in the research and development of Bitcoin and related protocols. Unlike the monthly speaker event, the Socratic Seminar events are formatted to foster debate, information sharing and lively discussion. Discussion topics from a variety of sources are collated by meetup members in the weeks preceding the events. We investigate pull requests in the Bitcoin Core, lnd, grin and other relevant repositories; we study network statistics, research papers, technical blog posts and other interesting content. To complete the meeting, members present open source projects, companies, research and other relevant materials. A feedback and Q&A section follow. A newsletter is sent out the day of the event which outlines discussion topics. Archives of discussion topics and presentations can be found in the event descriptions of past meetups. The discussion portion of the event is NEVER recorded. It is recommended that you have a firm grasp of the basics of Bitcoin in order to extract the most value from our Socratic events. Please contact the organizers if you'd like to present at a future Socratic event or have a recommended topic for discussion: leishman3 at gmail. There are different requirements for presentation depending on the type of project. Tentative list of discussion topics: Bitcoin PRs Disable nlocktime-based anti-fee sniping https://bitcoinops.org/en/newsletters/2019/01/15/ Overhaul importmulti logic https://github.com/bitcoin/bitcoin/pull/14565 Dandelion delays https://github.com/bitcoin/bitcoin/pull/13947 Allow connections from misbehaving banned peers https://github.com/bitcoin/bitcoin/pull/14929 Lightning PRs Enable plugin flag in c-lightning https://github.com/ElementsProject/lightning/issues/2244 Heuristic dry run option LND https://github.com/lightningnetwork/lnd/pull/2350 Memory reduction for nodes with many channels https://github.com/lightningnetwork/lnd/pull/2474 Sphinx send https://github.com/lightningnetwork/lnd/pull/2455 Peer management in Joule https://github.com/wbobeirne/joule-extension/pull/131 News Weak nonce attack against incorrectly generated ECDSA signatures: https://eprint.iacr.org/2019/023.pdf Bitcoin IRC logs https://twitter.com/Snyke/status/1078727327150997504 Grin Launch https://grinexplorer.net/ ETC Attack https://medium.com/@slowmist/the-analysis-of-etc-51-attack-from-slowmist-team-728596d76ead Stats LN Stats https://bitcoinvisuals.com/lightning Hashrate distribution https://coinmetrics.io/mining-pool-mapping/ Equal Output Txs https://twitter.com/nopara73/status/1080371795985874944 Bitmain mining share https://twitter.com/TradeBlock/status/1078712699360608256

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  • Socratic Seminar #5

    DG717

    Inspired by Bitdevs NY, this is an event for those interested in discussing and participating in the research and development of Bitcoin and related protocols. Unlike the monthly speaker event, the Socratic Seminar events are formatted to foster debate, information sharing and lively discussion. Discussion topics from a variety of sources are collated by meetup members in the weeks preceding the events. We investigate pull requests in the Bitcoin Core, lnd, grin and other relevant repositories; we study network statistics, research papers, technical blog posts and other interesting content. To complete the meeting, members present open source projects, companies, research and other relevant materials. A feedback and Q&A section follow. A newsletter is sent out the day of the event which outlines discussion topics. Archives of discussion topics and presentations can be found in the event descriptions of past meetups. The discussion portion of the event is NEVER recorded. It is recommended that you have a firm grasp of the basics of Bitcoin in order to extract the most value from our Socratic events. Please contact the organizers if you'd like to present at a future Socratic event or have a recommended topic for discussion: leishman3 at gmail. There are different requirements for presentation depending on the type of project. Tentative Topics for Discussion: Bitcoin Core Add ability to convert solvability info to descriptor https://github.com/bitcoin/bitcoin/pull/14477 Sighash Updates https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016488.html Deprecate “generate” RPC method https://github.com/bitcoin/bitcoin/pull/14468 Key Origin Support https://github.com/bitcoin/bitcoin/pull/14150 Never bind INADDR_ANY by default, https://github.com/bitcoin/bitcoin/pull/14532 Fix detection of copyright holders https://github.com/bitcoin/bitcoin/pull/14785 And more... Lightning New LND 5.1-beta release https://github.com/lightningnetwork/lnd/releases LND Remote signer https://github.com/lightningnetwork/lnd/issues/2081 LND Data loss protection merged https://github.com/lightningnetwork/lnd/pull/1937 CPFP Lightning Proposal https://lists.linuxfoundation.org/pipermail/lightning-dev/2018-November/001666.html C-Lightning Plugin subsystem https://github.com/ElementsProject/lightning/pull/2075 And more... News Blockstream open sources block explorer https://github.com/Blockstream/esplora Vertcoin 51% Attacked https://www.theblockcrypto.com/2018/12/03/long-tail-cryptocurrency-is-51-attacked-vertcoin-edition/ Simplicity Language Release https://blockstream.com/2018/11/28/simplicity-github/ Event Stream Vuln https://github.com/dominictarr/event-stream/issues/116 Meshcollider is New Wallet Maintainer https://twitter.com/meshcollider/status/1071244022436392960 Stats LN Stats https://bitcoinvisuals.com/lightning Bitcoin network stats https://dashboard.bitcoinops.org/ Largest ever UTXO https://twitter.com/khannib/status/1063068406981767170

  • Socratic Seminar #4 (in Mountain View)

    Blockstream Office

    IMPORTANT: This event is in Mountain View!!! Check the event location for details. Inspired by Bitdevs NY, this is an event for those interested in discussing and participating in the research and development of Bitcoin and related protocols. Unlike the monthly speaker event, the Socratic Seminar events are formatted to foster debate, information sharing and lively discussion. Discussion topics from a variety of sources are collated by meetup members in the weeks preceding the events. We investigate pull requests in the Bitcoin Core, lnd, grin and other relevant repositories; we study network statistics, research papers, technical blog posts and other interesting content. To complete the meeting, members present open source projects, companies, research and other relevant materials. A feedback and Q&A section follow. A newsletter is sent out the day of the event which outlines discussion topics. Archives of discussion topics and presentations can be found in the event descriptions of past meetups. The discussion portion of the event is NEVER recorded. It is recommended that you have a firm grasp of the basics of Bitcoin in order to extract the most value from our Socratic events. Please contact the organizers if you'd like to present at a future Socratic event or have a recommended topic for discussion: leishman3 at gmail. There are different requirements for presentation depending on the type of project.

  • Socratic Seminar #3

    DG717

    Details Inspired by Bitdevs NY, this is an event for those interested in discussing and participating in the research and development of Bitcoin and related protocols. Unlike the monthly speaker event, the Socratic Seminar events are formatted to foster debate, information sharing and lively discussion. Discussion topics from a variety of sources are collated by meetup members in the weeks preceding the events. We investigate pull requests in the Bitcoin Core, lnd, grin and other relevant repositories; we study network statistics, research papers, technical blog posts and other interesting content. To complete the meeting, members present open source projects, companies, research and other relevant materials. A feedback and Q&A section follow. A newsletter is sent out the day of the event which outlines discussion topics. Archives of discussion topics and presentations can be found in the event descriptions of past meetups. The discussion portion of the event is NEVER recorded. It is recommended that you have a firm grasp of the basics of Bitcoin in order to extract the most value from our Socratic events. Please contact the organizers if you'd like to present at a future Socratic event or have a recommended topic for discussion: leishman3 at gmail. There are different requirements for presentation depending on the type of project.

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  • Socratic Seminar #2

    DG717

    Inspired by Bitdevs NY, this is an event for those interested in discussing and participating in the research and development of Bitcoin and related protocols. Unlike the monthly speaker event, the Socratic Seminar events are formatted to foster debate, information sharing and lively discussion. Discussion topics from a variety of sources are collated by meetup members in the weeks preceding the events. We investigate pull requests in the Bitcoin Core, lnd, grin and other relevant repositories; we study network statistics, research papers, technical blog posts and other interesting content. To complete the meeting, members present open source projects, companies, research and other relevant materials. A feedback and Q&A section follow. A newsletter is sent out the day of the event which outlines discussion topics. Archives of discussion topics and presentations can be found in the event descriptions of past meetups. The discussion portion of the event is NEVER recorded. It is recommended that you have a firm grasp of the basics of Bitcoin in order to extract the most value from our Socratic events. Please contact the organizers if you'd like to present at a future Socratic event or have a recommended topic for discussion: leishman3 at gmail. There are different requirements for presentation depending on the type of project. Potential Topics Bitcoin PRs: Group Coin Selection Option https://github.com/bitcoin/bitcoin/pull/12257 Bitcoin Optech Newsletter 8: https://bitcoinops.org/en/newsletters/2018/08/21/ P2P Encryption: https://github.com/bitcoin/bitcoin/pull/14032 AVX512 intrinsic: https://github.com/bitcoin/bitcoin/pull/13989/files Dandelion Implementation: https://github.com/bitcoin/bitcoin/pull/13947 Min relay fee: https://github.com/bitcoin/bitcoin/pull/13922 Anti-DoS Locator limit: https://github.com/bitcoin/bitcoin/pull/13907 Compact Block Filter: https://github.com/bitcoin/bitcoin/pull/12254 Property Based Testing: https://github.com/bitcoin/bitcoin/pull/8469 Lightning Arbitrary Contracts over Lightning https://lists.linuxfoundation.org/pipermail/lightning-dev/2018-August/001387.html LND v0.5 https://github.com/lightningnetwork/lnd/milestone/7 C-lightning v0.6.1 https://github.com/ElementsProject/lightning/issues?q=is%3Aopen+is%3Aissue+milestone%3Av0.6.1 Mimblewimble Cuckoo Cycles No Longer ASIC resistant https://github.com/tromp/cuckoo/commit/c809117d84759909a15a504c92435cfda166fe79 Security Vulnerabilities Cory Fields Vuln from Bitcoin Cash https://medium.com/mit-media-lab-digital-currency-initiative/http-coryfields-com-cash-48a99b85aad4 Other Stuff Rust in-memory blockchain store https://github.com/rust-bitcoin/rust-blockchain-store Tadge Dryja - Accumulators for UTXO commitments https://twitter.com/tdryja/status/1030902523077451776 No write up about it, but utreexo is a clue. Anyone have any more information about this? Pay to Endpoint https://blockstream.com/2018/08/08/improving-privacy-using-pay-to-endpoint.html Chia BLS Lib https://github.com/Chia-Network/bls-signatures Stats and Events Xapo UTXO Consolidation https://bitcoinops.org/en/xapo-utxo-consolidation/ Lightning Network Stats https://p2sh.info/dashboard/db/lightning-network?orgId=1&from=1527572205519&to=1532756205519 OP_RETURN https://p2sh.info/dashboard/db/op_return-statistics?orgId=1 Security Breaking the Virtual Memory Abstraction with Transient Out-of-Order Execution https://foreshadowattack.eu/ Homebrew Hack https://medium.com/@vesirin/how-i-gained-commit-access-to-homebrew-in-30-minutes-2ae314df03ab

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