Technical articles on architecture, security, and the systems behind our products.
-
Encrypting App Data at Rest on macOS
September 13, 2026
Entelecheia builds software for handling confidential data, and secure local storage is foundational to that work. We’re open-sourcing our approach to storing data securely on …
-
JavaScript Backdoors and Page Integrity
September 5, 2026
In an effort to make the web safer, Entelecheia is sharing this proposed architecture with browser developers, standards organizations, and others working on the future of the web. …
-
Hiding Text in a Numeric ID
September 2, 2026
When designing IDs that a person may need to read, copy, type, or pass to someone else, usability matters as much as uniqueness. A lookup ID may have to be dictated over the phone, …
-
Shoulder Surfing QR Codes: A Defense
August 19, 2026
QR codes are a convenient way to pair a mobile device with a desktop application or a web application running on the desktop: the desktop displays a code, and the phone scans it. …
-
Sanitizing PDFs Uploaded by Users
July 11, 2026
PDFs uploaded by users should be treated as untrusted files. A document may have come from a scanner or a word processor, but a PDF is capable of containing much more than the text …
-
Sanitizing Images Uploaded by Users
June 27, 2026
Images uploaded by users should be treated as untrusted files. We focus on JPEG because, in most cases, an image uploaded by a user can simply be converted to JPEG first (if it’s …
-
Capital Hold: A Defense Against Malicious Servers
April 16, 2026
We usually think of a denial-of-service attack as something directed at a server. An attacker sends traffic toward a target until it can no longer cope. But a malicious server can …