Fast, Metadata-private Anonymous Broadcast
This thesis presents Trellis: a mix-net based anonymous broadcast system with cryptographic security guarantees. Trellis can be used to anonymously publish documents or communicate with other users, all while assuming full network surveillance. In Trellis, users send messages through a set of server...
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Format: | Thesis |
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Massachusetts Institute of Technology
2023
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Online Access: | https://hdl.handle.net/1721.1/147411 |
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author | Langowski, Simon |
author2 | Devadas, Srinivas |
author_facet | Devadas, Srinivas Langowski, Simon |
author_sort | Langowski, Simon |
collection | MIT |
description | This thesis presents Trellis: a mix-net based anonymous broadcast system with cryptographic security guarantees. Trellis can be used to anonymously publish documents or communicate with other users, all while assuming full network surveillance. In Trellis, users send messages through a set of servers in successive rounds. The servers mix and post the messages to a public bulletin board, hiding which senders sent which messages.
Trellis hides all network-level metadata, remains robust to changing network conditions, guarantees availability to honest users, and scales with the number of mix servers. Trellis provides three to five orders of magnitude faster performance and better network robustness compared to Atom, the state-of-the-art anonymous broadcast system with a similar threat model.
In achieving these guarantees, Trellis contributes: (1) a simpler theoretical mixing analysis for a routing mix network constructed with a fraction of malicious servers, (2) anonymous routing tokens for verifiable random paths, and (3) lightweight blame protocols built on top of onion routing to identify and eliminate malicious parties.
We implement and evaluate Trellis in a networked deployment. With 32 servers located across four geographic regions, Trellis achieves a throughput of 200 bits per second with 100,000 users. With 64 servers, Trellis achieves a throughput of 320 bits per second. Trellis’s throughput is only 100 to 1000× slower compared to Tor (which has 2M daily users) and is therefore potentially deployable at a smaller “enterprise” scale. Our implementation is open-source. |
first_indexed | 2024-09-23T14:36:30Z |
format | Thesis |
id | mit-1721.1/147411 |
institution | Massachusetts Institute of Technology |
last_indexed | 2024-09-23T14:36:30Z |
publishDate | 2023 |
publisher | Massachusetts Institute of Technology |
record_format | dspace |
spelling | mit-1721.1/1474112023-01-20T03:17:10Z Fast, Metadata-private Anonymous Broadcast Langowski, Simon Devadas, Srinivas Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science This thesis presents Trellis: a mix-net based anonymous broadcast system with cryptographic security guarantees. Trellis can be used to anonymously publish documents or communicate with other users, all while assuming full network surveillance. In Trellis, users send messages through a set of servers in successive rounds. The servers mix and post the messages to a public bulletin board, hiding which senders sent which messages. Trellis hides all network-level metadata, remains robust to changing network conditions, guarantees availability to honest users, and scales with the number of mix servers. Trellis provides three to five orders of magnitude faster performance and better network robustness compared to Atom, the state-of-the-art anonymous broadcast system with a similar threat model. In achieving these guarantees, Trellis contributes: (1) a simpler theoretical mixing analysis for a routing mix network constructed with a fraction of malicious servers, (2) anonymous routing tokens for verifiable random paths, and (3) lightweight blame protocols built on top of onion routing to identify and eliminate malicious parties. We implement and evaluate Trellis in a networked deployment. With 32 servers located across four geographic regions, Trellis achieves a throughput of 200 bits per second with 100,000 users. With 64 servers, Trellis achieves a throughput of 320 bits per second. Trellis’s throughput is only 100 to 1000× slower compared to Tor (which has 2M daily users) and is therefore potentially deployable at a smaller “enterprise” scale. Our implementation is open-source. S.M. 2023-01-19T19:48:23Z 2023-01-19T19:48:23Z 2022-09 2022-10-19T18:57:37.858Z Thesis https://hdl.handle.net/1721.1/147411 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology |
spellingShingle | Langowski, Simon Fast, Metadata-private Anonymous Broadcast |
title | Fast, Metadata-private Anonymous Broadcast |
title_full | Fast, Metadata-private Anonymous Broadcast |
title_fullStr | Fast, Metadata-private Anonymous Broadcast |
title_full_unstemmed | Fast, Metadata-private Anonymous Broadcast |
title_short | Fast, Metadata-private Anonymous Broadcast |
title_sort | fast metadata private anonymous broadcast |
url | https://hdl.handle.net/1721.1/147411 |
work_keys_str_mv | AT langowskisimon fastmetadataprivateanonymousbroadcast |