Hello, I’m redshiftzero. My interests span physics, cryptography, and civic technology. I currently work at Penumbra Labs on applied cryptography in Rust. Previously I’ve worked at Freedom of the Press Foundation as the lead developer of the SecureDrop project and a principal research engineer. Prior to that I was a postdoc researcher at the Center for Data Science and Public Policy (now at Carnegie Mellon). I completed my Ph.D. in Astrophysics in 2015 at the University of Chicago’s Kavli Institute of Cosmological Physics.
Previous Projects
Cryptography
- decaf377: An elliptic-curve library in Rust - a prime-order group designed for use in SNARKs over BLS12-377. Work done while at Penumbra Labs.
- poseidon377: a suite of Rust crates for the Poseidon1 and Poseidon2 hash functions. Work done while at Penumbra Labs.
Astrophysics
- cosmocalc.rs: A library for computing cosmological distances in Rust.
- cosmowebapp: A d3.js interactive visualization of cosmological (matter and CMB) power spectra. Joint with Eric Baxter (Hawaii IfA).
Civic technology
- SecureDrop: A tool for news organizations to communicate with sources. The full list of organizations using SecureDrop can be seen in the directory here.
- OpenOversight: A tool for police oversight in use on the Burlington VT, Chicago, Oakland, Berkeley, and UC Berkeley Police Departments, as well as in Baltimore.
- City of Cincinnati building code prediction (during 2015 Data Science for Social Good): blog GitHub repository.
- Data-Driven Early Intervention System for police departments: GitHub repository. Currently developed by CMU and Benchmark Analytics.
Papers
A Complete Census of Circumgalactic MgII at Redshift z ≲ 0.5 Yun-Hsin Huang, Hsiao-Wen Chen, Stephen A. Shectman, Sean D. Johnson, Fakhri S. Zahedy, Jennifer E. Helsby , Jean-René Gauthier, Ian B. Thompson, submitted to MNRAS, 2020.
Early intervention systems: Predicting adverse interactions between police and the public Jennifer Helsby , Samuel Carton, Kenneth Joseph, Ayesha Mahmud, Youngsoo Park, Andrea Navarrete, Klaus Ackermann, Joe Walsh, Lauren Haynes, Crystal Cody, Major Estella Patterson, Rayid Ghani, Criminal Justice Policy Review, 2018.
Early detection of properties at risk of blight using spatiotemporal data Eduardo Blancas Reyes, Jennifer Helsby , Katharina Rasch, Paul van der Boor, Rayid Ghani, Lauren Haynes and Edward P. Cunningham, Data for Policy, 2016.
Identifying Police Officers at Risk of Adverse Events, Samuel Carton, Jennifer Helsby , Kenneth Joseph, Ayesha Mahmud, Youngsoo Park, Joe Walsh, Crystal Cody, CPT Estella Patterson, Lauren Haynes, Rayid Ghani, Proceedings of the 22nd ACM SIGKDD international conference on knowledge discovery and data mining, 2016.
The dark energy survey and operations: years 1 to 3 H Thomas Diehl, Eric Neilsen, R Gruendl, Brian Yanny, TMC Abbott, Jelena Aleksić, S Allam, J Annis, Eduardo Balbinot, M Baumer, Lucas Beaufore, Keith Bechtol, G Bernstein, Simon Birrer, Christopher Bonnett, Dillon Brout, Claudio Bruderer, EJ Buckley-Geer, Diego Capozzi, A Carnero Rosell, Francisco J Castander, R Cawthon, C Chang, L Clerkin, R Covarrubias, C Cuhna, C D’Andrea, L Da Costa, Ramashis Das, C Davis, J Dietrich, Alex Drlica-Wagner, Anne Elliott, Tim F Eifler, James Etherington, BL Flaugher, Joshua Frieman, A Fausti Neto, MG Fernández, Christina Furlanetto, D Gangkofner, David W Gerdes, Daniel A Goldstein, Kathleen Grabowski, Ravi R Gupta, S Hamilton, H Head, J Helsby , D Hollowood, Klaus Honscheid, D James, M Johnson, MWG Johnson, Stéphanie Jouvel, T Kacprzac, Stephen Kent, R Kessler, A Kim, Elisabeth Krause, Christina I Krawiec, A Kremin, R Kron, S Kuhlmann, N Kuropatkin, O Lahav, J Lasker, TS Li, E Luque, N Maccrann, M March, J Marshall, NP Mondrik, EP Morganson, D Mudd, A Nadolski, P Nugent, P Melchior, F Menanteau, DQ Nagasawa, B Nord, R Ogando, L Old, A Palmese, D Petravick, AA Plazas, A Pujol, ABA Queiroz, K Reil, AK Romer, R Rosenfeld, A Roodman, P Rooney, M Sako, AI Salvador, C Sánchez, E Sánchez Álvaro, BX Santiago, A Schooneveld, M Schubnell, E Sheldon, A Smith, RC Smith, M Soares-Santos, F Sobreira, M Soumagnac, H Spinka, SS Tie, D Tucker, V Vikram, K Vivas, AR Walker, W Wester, M Wiesner, H Wilcox, P Williams, A Zenteno, Y Zhang, Z Zhang, Observatory Operations: Strategies, Processes, and Systems, 2016.
Observation and Confirmation of Six Strong Lensing Systems in The Dark Energy Survey Science Verification Data B. Nord, E. Buckley-Geer, H. Lin, H. T. Diehl, J. Helsby , N. Kuropatkin, A. Amara, T. Collett, S. Allam, G. Caminha, C. De Bom, S. Desai, H. Dúmet-Montoya, M. Elidaiana da S. Pereira, D. A. Finley, B. Flaugher, C. Furlanetto, H. Gaitsch, M. Gill, K. W. Merritt, A. More, D. Tucker, E. S. Rykoff, E. Rozo, F. B. Abdalla, A. Agnello, M. Auger, R. J. Brunner, M. Carrasco Kind, F. J. Castander, C. E. Cunha, L. N. da Costa, R. Foley, D. W. Gerdes, K. Glazebrook, J. Gschwend, W. Hartley, R. Kessler, D. Lagattuta, G. Lewis, M. A. G. Maia, M. Makler, F. Menanteau, A. Niernberg, D. Scolnic, J. D. Vieira, R. Gramillano, T. M. C. Abbott, M. Banerji, A. Benoit-Lévy, D. Brooks, D. L. Burke, D. Capozzi, A. Carnero Rosell, J. Carretero, C. B. D’Andrea, J. P. Dietrich, P. Doel, A. E. Evrard, J. Frieman, E. Gaztanaga, D. Gruen, K. Honscheid, D. J. James, K. Kuehn, T. S. Li, M. Lima, J. L. Marshall, P. Martini, P. Melchior, R. Miquel, E. Neilsen, R. C. Nichol, R. Ogando, A. A. Plazas, A. K. Romer, M. Sako, E. Sanchez, V. Scarpine, M. Schubnell, I. Sevilla-Noarbe, R. C. Smith, M. Soares-Santos, F. Sobreira, E. Suchyta, M. E. C. Swanson, G. Tarle, J. Thaler, A. R. Walker, W. Wester, Y. Zhang, the DES Collaboration, The Astrophysical Journal, 2015.
The dark energy survey and operations: Year 1 HT Diehl, TMC Abbott, J Annis, R Armstrong, L Baruah, A Bermeo, G Bernstein, E Beynon, C Bruderer, EJ Buckley-Geer, H Campbell, D Capozzi, M Carter, R Casas, L Clerkin, R Covarrubias, C Cuhna, C D’Andrea, L Da Costa, R Das, DL DePoy, J Dietrich, A Drlica-Wagner, A Elliott, T Eifler, J Estrada, J Etherington, BL Flaugher, J Frieman, A Fausti Neto, M Gelman, D Gerdes, D Gruen, R Gruendl, J Hao, H Head, J Helsby , K Hoffman, K Honscheid, D James, M Johnson, T Kacprzac, J Katsaros, R Kennedy, S Kent, R Kessler, A Kim, E Krause, R Kron, S Kuhlmann, A Kunder, T Li, H Lin, N Maccrann, M March, J Marshall, E Neilsen, P Nugent, P Martini, P Melchior, F Menanteau, RC Nichol, B Nord, R Ogando, L Old, A Papadopoulos, K Patton, D Petravick, AA Plazas, R Poulton, A Pujol, K Reil, T Rigby, A Romer, A Roodman, P Rooney, E Sanchez Alvaro, S Serrano, E Sheldon, A Smith, RC Smith, M Soares-Santos, M Soumagnac, H Spinka, E Suchyta, D Tucker, AR Walker, W Wester, M Wiesner, H Wilcox, R Williams, B Yanny, Y-Y Zhang, Observatory Operations: Strategies, Processes, and Systems, 2014.
SGAS 143845.1+ 145407: A Big, Cool Starburst at Redshift 0.816 Michael D. Gladders, Jane R. Rigby, Keren Sharon, Eva Wuyts, Louis E. Abramson, Håkon Dahle, S. E. Persson, Andrew J. Monson, Daniel D. Kelson, Dominic J. Benford, David Murphy, Matthew B. Bayliss, Keely D. Finkelstein, Benjamin P. Koester, Alissa Bans, Eric J. Baxter, and Jennifer E. Helsby, The Astrophysical Journal, 2013.
What Determines the Incidence and Extent of MgII Absorbing Gas Around Galaxies? Hsiao-Wen Chen, Vivienne Wild, Jeremy L. Tinker, Jean-Rene Gauthier, Jennifer E. Helsby , Stephen A. Shectman, Ian B. Thompson, The Astrophysical Journal Letters, 2010.
An empirical characterization of extended cool gas around galaxies using Mg II absorption features Hsiao-Wen Chen, Jennifer E Helsby , Jean-René Gauthier, Stephen A Shectman, Ian B Thompson, Jeremy L Tinker, The Astrophysical Journal, 2010.
Performance Expectations for a Tomography System Using Cosmic Ray Muons and Micro Pattern Gas Detectors for the Detection of Nuclear Contraband Kondo Gnanvo, Patrick Ford, Jennifer Helsby , Richie Hoch, Debasis Mitra, Marcus Hohlmann, IEEE Nuclear Science Symposium Conference Record, 2008.
GEANT4 Simulation of a Cosmic Ray Muon Tomography System with Micro-Pattern Gas Detectors for the Detection of High-Z Materials Marcus Hohlmann, Patrick Ford, Kondo Gnanvo, Jennifer Helsby , David Pena, Richard Hoch, Debasis Mitra, IEEE Transactions on Nuclear Science, 2009.
Media
- Coverage of City of Cincinnati building code violation prediction: Wired/Backchannel
- Coverage of predictive EIS: Mother Jones, FiveThirtyEight, NPR, wsoctv
- Coverage of Lucy Parsons Labs’ OpenOversight: Citylab, Chicagoist, Washington Times
Teaching
University of Chicago, PPHA 30530: Computation for Public Policy, Winter 2016. Graduate-level introductory data analysis course (Python, SQL) aimed at public policy students.
Talks
A subset of my talks, some others are on Speakerdeck and Youtube.
Next-Generation SecureDrop: Protecting Journalists from Malware, USENIX Enigma 2020. Video.
Early Warning/Intervention Systems, National Association for Civilian Oversight of Law Enforcement (NACOLE) Symposium 2016 Video.