Hello, I’m redshiftzero. I like physics and cryptography. Below is an incomplete list of some of my previous work.

Google Scholar




Professional Experience

Penumbra Labs

Core Engineer: September 2021-present

Independent Consultant

June-September 2021

Consulting for private clients

Freedom of the Press Foundation

Principal Research Engineer, July 2020 - June 2021

SecureDrop Lead Developer, July 2017 - June 2020

Ford-Mozilla Open Web Fellow, September 2016 - June 2017

Center for Data Science and Public Policy

Postdoctoral Researcher, September 2015 - September 2016

Data Science for Social Good Technical Mentor, June 2016 - August 2016

Data Science for Social Good Fellow, June 2015 - August 2015


University of Chicago, PPHA 30530: Computation for Public Policy, Winter 2016. Graduate-level introductory data analysis course (Python, SQL) aimed at public policy students.


University of Chicago, Ph.D. Astrophysics, completed June 2015

Previous Projects

  • SecureDrop. I was a maintainer (from 2016-2021) and previously was the project lead (from 2017-2020). This project is a whistleblowing platform used by news organizations to communicate with sources. The full list of sites using SecureDrop can be seen in the directory here.
  • OpenOversight. I started this project in 2016 and it’s now maintained by LPL volunteers. This project is a webapp that makes it easier for the public to identify police officers, including for the purpose of complaints. It relies on crowdsourced and public data to build a database of police officers in a city. It is currently in use on the Burlington VT, Chicago, Oakland, Berkeley, and UC Berkeley Police Departments. The codebase is also used by Portland and 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.


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.


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.