--- title: 2024-05-06 Nomos weekly tags: - nomos-updates date: 2024-05-06 lastmod: 2024-05-06 draft: false description: Weekly update of Nomos --- ## `P2P Privacy` ### `Research` - To specify adversary models, we analyzed and summarized two papers: [2013 P. Syverson](https://www.notion.so/Why-I-m-Not-an-Entropist-f96c5eca9c924dc6a1f23903188a625d "2013 P. Syverson") & [2023 C. Diaz](https://www.notion.so/Traffic-Analysis-by-Adversaries-with-Partial-Visibility-a8abbe41780f4631bbbbeaca16dc286c "2023 C. Diaz"). - Based on the above research, we defined the adversary model in the [Mixnet v2: Proof of Concept](https://www.notion.so/Mixnet-v2-Proof-of-Concept-102d0563e75345a3a6f1c11791fbd746?pvs=4#62a2e9ccf0c745c4b3aca9dd5ef0e723 "Mixnet v2: Proof of Concept"), focusing on adversaries with partial visibility. Still, specific attack models must be defined so that we can simulate them. Currently, we are attempting things in reverse: imagining attacks that partially or completely break the protections that our design aims to provide. It's still a work in progress in [the same Notion page](https://www.notion.so/Mixnet-v2-Proof-of-Concept-102d0563e75345a3a6f1c11791fbd746?pvs=4#6f964a5ac1144239a17ad5d3e648746d "the same Notion page"). Once this is complete, we can start implementing a simulation. - Based on the previous week's observations, we wrote a [document](https://www.notion.so/Weakening-The-Tagging-Attack-e3b085102ca6455da0747ca64e725ff6#6dce376ef65948928d38aa64e277a9d6) containing a discussion on how to make the tagging attack less effective. - Analysis of anonymity and communication failures in the mix gadget ([summary](https://www.notion.so/Analysis-of-failures-in-the-mix-network-feeef349720842759c59785af71c7c59?pvs=4#5354ec4b641743709a2429327ef00ed3)): Assuming that n nodes sample (with replacement) k nodes from the population with N nodes, where at most M nodes are adversarial, the fraction of k-subsets where all k nodes are adversarial, i.e., “anonymity failure” has occurred, is \left(\frac{M}{N}\right)^k on average. The fraction of k-subsets where at least one node is adversarial, i.e., “communication failure” has occurred, is 1 - \left(1 - \frac{M}{N}\right)^k on average. However, if n < N is finite, then deviation from these averages will be observed. For the fraction of k-subsets with anonymity failure, we derived an upper bound on the probability that the fraction of these k-subsets is greater than the average \left(\frac{M}{N}\right)^k by the factor of 1+γ. The upper bound is decreasing with increasing n and γ. A similar upper bound is derived for the fraction of k-subsets with communication failure. Work on the analysis of these bounds and verification by simulation is currently in progress. ### `Development` - No updates this week. ## `Data Availability` ### `Research` - No updates this week. ### `Development` - DA Indexer implementation [PR](https://github.com/logos-co/nomos-node/pull/644): Implemented `AddIndex` and `GetRange` functionality in Indexer service. When a list of VidCertificates is observed in a new Block, `AddIndex` is used to assign Metadata from VidCertificate to a blob that was attested. - When the user requests Range of Indexes for a given AppId, indexer collects available blobs for indexes and returns them in a list. - DA Indexer + Mempool + Cryptarchia integration test: DA functionality relies on multiple services working together; a test to see if currently implemented parts are working was created. - Some ideas and improvements were registered (low priority): [Verified Certificate state](https://github.com/logos-co/nomos-node/issues/646) and [Investigate BlobDB storage](https://github.com/logos-co/nomos-node/issues/645). ## `PPoS/Consensus` ### `Research` - [Wealth concentration update](https://www.notion.so/Does-Crypsinous-Leader-Election-Function-lead-to-wealth-concentration-in-PoS-b81f07a791b745438443f51f00ac258f): changes related to the introduction of the study structure, rearrangement based on new sections, and expanded explanations. ### `Development` - No updates this week. ## `Coordination Layer` ### `Research` - Designed a bridge withdrawal implementation. In designing, we found some bugs in CL, namely, anoma's "single logic per resource" design is too limiting; it wasn't possible to see how to implement a simple withdrawal in that design. The fix that was made was borrowed from Zexe, replacing the single note constraint with two types of constraints: birth and death constraints. There is a single birth constraint and arbitrarily many death constraints. Birth constraints govern how a note from a particular application can be produced. Death constraints are provided by the user and configure how a note can be spent; only one of the death constraints needs to be satisfied in order to spend a note. - Created the withdrawal CL [test case](https://www.notion.so/CL-Specification-9a60bd41167d426abb0cd07a01aab905#65e0cc1439fb4ac2ac63be5859b942bc). - Updated the [Proof Systems](https://www.notion.so/Proof-Systems-Survey-ffc625a2ff82407db7a45fd193136258) survey according to comments. Explanations have been added to some of the sections. Additionally, existing zkp libraries have been reviewed to identify which proof methods are used. - Coordination Layer Studies: a separate [section](A separate section for FRI has been added) for FRI has been added. ### `Development` - No updates this week. ## `Testnet + Insights` ### `Research` - No updates this week. ### `Development` - No updates this week. ## `User Tools` ### `Research` - No updates this week. ### `Development` - No updates this week. ## `Miscellaneous` - No updates this week.