CMU (current, PhD in CS)
Cambridge ('19, MPhil in CS)
Caltech ('18, BS in Math)
I am a computer science PhD
student at CMU, advised by Heather Miller
. I am supported by an NDSEG Fellowship
sponsored by the US Office of Naval Research
My current research focuses on tools for building decentralized systems, including conflict-free replicated data types and secure group messaging protocols. Previously, I studied error-correcting code algorithms and algebraic number theory.
- M. Weidner and P. S. Almeida. An Oblivious Observed-Reset Embeddable Replicated Counter. PaPoC 2022. official (open access) slides
- Designing for Eventual Consistency with Simple, Composable CRDTs. Talk at UCSC Languages, Systems, and Data Seminar, 2/18/2022. slides blog post
- Collaborative Apps over Matrix using the Collabs Library. Lightning talk at FOSDEM 2022 - Matrix.org Foundation & Community devroom. talk page slides
- @collabs/collabs: A TypeScript collections library for collaborative data structures. npm package github demos
- M. Weidner and H. Miller. Making Webapps Collaborative with Composable CRDTs. Strange Loop 2021. video talk info page slides recipe book demo LAN demo (electron) LAN demo (localhost server)
- M. Weidner, M. Kleppmann, D. Hugenroth, and A. R. Beresford. Key Agreement for Decentralized Secure Group Messaging with Strong Security Guarantees. Proceedings of the 2021 ACM SIGSAC Conference on Computer and Communications Security (CCS '21). official (open access) extended version
- M. Weidner, H. Miller, and C. Meiklejohn. Composing and Decomposing Op-Based CRDTs with Semidirect Products. Proceedings of ACM Programming Languages 4 (ICFP), Article 94, August 2020. official (open access) slides talk
- M. Weidner. Group messaging for secure asynchronous collaboration. MPhil Dissertation, University of Cambridge, 2019. Advisors: A. R. Beresford and M. Kleppmann. pdf
- A. K. Narayanan and M. Weidner. On decoding Cohen-Haeupler-Schulman tree codes. Presented at Symposium on Discrete Algorithms (SODA) 2020. official pdf slides
- A. K. Narayanan and M. Weidner. Subquadratic time encodable codes beating the Gilbert-Varshamov bound. IEEE Transactions on Information Theory, 65(10):6010-6021, October 2019. official pdf
- A. Chiesa, L. Chua, and M. Weidner. On cycles of pairing-friendly elliptic curves. SIAM Journal on Applied Algebra and Geometry, 3(2):175-192, 2019. official pdf
- M. Weidner. Pseudocharacters of homomorphisms into classical groups. Transformation Groups, 25:1345-1370, 2020. offical pdf
- M. Weidner. On conjectural rank parities of quartic and sextic twists of elliptic curves. International Journal of Number Theory, 15(9):1895-1918, June 2019. official arXiv code
- M. Weidner. Towards fast encoding of Garcia-Stichtenoth algebraic
geometry codes. SURF Final Report, 2018. Advisors: A. K. Narayanan and C. Umans. pdf
- M. Hadian and M. Weidner. On Selmer rank parity of twists. Journal of the Australian Mathematical Society, 102(3):316-330, June 2017. official preprint
Works in Progress
Verify proofs before trusting!
- Slides about a simple list/text CRDT, targeted at a general CS audience. Originally presented at CMU's PLunch. The CRDT itself fits on a single slide. This is what Collabs uses for its lists, and it's also equivalent to the "Double RGA" mentioned below.
- Draft of a proof that doubly non-interleaving list CRDTs (desirable for collaborative text editing) are impossible, for even a weak definition of non-interleaving. However, you can get pretty close using a novel list CRDT I call "Double RGA".
Math is Fun?
Here is a list of math jokes
, compiled by Laura Shou
Here is a packet of "fun" math problems
, compiled from various sources by a group including William Hoza
, Laura Shou
, Jalex Stark
, Michael Wheeler, and myself. They are designed to be printed double sided and cut in two, so that each problem has a link to its "answer" on the back.
• PhD student at CMU CSD