awn umar

Programmer mostly working on security stuff. Mathematics and computer science at the University of Bristol. Here I post about things I’m working on or thinking about.

recent posts

• 2024-07-23 : : how monzo generates sensitive secrets for its banking platform
• 2022-02-15 : : securely delegating trust with signatures and key management
• 2020-12-16 : : rosen: censorship-resistant proxy tunnel
• 2020-02-20 : : plausibly deniable encryption
• 2019-07-20 : : memory retention attacks
• 2019-07-18 : : encrypting secrets in memory
• 2019-06-27 : : mutable strings in go
• 2019-05-02 : : to slice or not to slice
• 2017-08-03 : : memory security in go
• 2017-07-30 : : quantum key-exchange

projects

• memguard : : secure software enclave for storage of sensitive information in memory
• rosen : : modular proxy tunnel that circumvents censorship by encapsulating traffic within a cover protocol
• gravity : : experimental user-space data protection utility providing plausibly deniable encryption
• ephemeral : : web-based end-to-end encrypted multi-party chat server

papers

Obfuscating Network Traffic to Circumvent Censorship [pdf]

Explore widely used network traffic fingerprinting and obfuscation techniques. Introduce a modular proxy tunnel framework and evaluate it against state-of-the- art DPI engines and a nation-state adversary.

Minimal Surface Theory: The Mathematics of Soap Films [pdf]

An introduction to minimal surfaces and their relation to soap films, and some ways that they can be created.