Some (not so serious) cryptographic wisdom\nfrom a long time ago\u2026
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/09/22/reinforcement-learning-formulas/", "title": "Reinforcement Learning formulas cheat sheet", "url": "https://www.gabriel.urdhr.fr/2025/09/22/reinforcement-learning-formulas/", "date_published": "2025-09-22T00:00:00+02:00", "date_modified": "2025-09-22T00:00:00+02:00", "tags": ["computer", "machine-learning", "reinforcement-learning", "neural-networks"], "content_html": "Cheat sheet for (some) reinforcement learning mathematical formulas and algorithms.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/08/22/concealing-xss-payload/", "title": "Concealing XSS payloads", "url": "https://www.gabriel.urdhr.fr/2025/08/22/concealing-xss-payload/", "date_published": "2025-08-22T00:09:04+02:00", "date_modified": "2025-08-22T00:09:04+02:00", "tags": ["computer", "security", "xss", "waf"], "content_html": "PortSwigger \u201cConcealing payloads in URL credentials\u201d\ntalks about concealing XSS payloads in URL credentials.\nThe nice thing is that this makes the payload invisible to WAFs and other server-side XSS filters.\nYou can actually conceal the payloads in other places
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/08/22/codingame-spring-challenge-2025/", "title": "Codingame Spring Challenge 2025", "url": "https://www.gabriel.urdhr.fr/2025/08/22/codingame-spring-challenge-2025/", "date_published": "2025-08-22T00:00:00+02:00", "date_modified": "2025-08-22T00:00:00+02:00", "tags": ["computer", "rust", "optimisation", "profiling", "flamegraph"], "content_html": "My experience from the Codingame Spring Challenge 2025.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/08/20/unicode-tag-smuggling/", "title": "Testing Unicode Tag Smuggling in chatbots", "url": "https://www.gabriel.urdhr.fr/2025/08/20/unicode-tag-smuggling/", "date_published": "2025-08-20T00:00:00+02:00", "date_modified": "2026-01-16T01:06:36+01:00", "tags": ["computer", "security", "language-model", "LLM"], "content_html": "Testing ASCII smuggling\nusing Unicode Tags\non LLMs/chatbots.\nNothing new here.\nJust a short summary.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/07/08/books-2024/", "title": "Books I have read in 2024", "url": "https://www.gabriel.urdhr.fr/2025/07/08/books-2024/", "date_published": "2025-07-08T00:00:00+02:00", "date_modified": "2025-07-08T00:00:00+02:00", "tags": ["book", "cryptography", "society"], "content_html": "Books I have read in 2024.\nTries to avoid spoiling as much as possible\nand therefore does not contain a very deep analysis or review of most books.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/07/08/keycloak-uma-vulnerabilities/", "title": "Keycloak UMA vulnerabilities", "url": "https://www.gabriel.urdhr.fr/2025/07/08/keycloak-uma-vulnerabilities/", "date_published": "2025-07-08T00:00:00+02:00", "date_modified": "2025-07-08T00:00:00+02:00", "tags": ["computer", "protocol", "web", "security", "oauth", "keycloak", "security", "uma", "openid-connect"], "content_html": "Keycloak's UMA implementation seems tricky to me.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/05/14/llama.cpp-quickstart/", "title": "llama.cpp quickstart", "url": "https://www.gabriel.urdhr.fr/2025/05/14/llama.cpp-quickstart/", "date_published": "2025-05-14T23:12:16+02:00", "date_modified": "2025-05-14T23:12:16+02:00", "tags": ["computer", "machine-learning", "deep-learning", "language-model", "neural-networks", "LLM"], "content_html": "How to quickly use llama.cpp for LLM inference (no GPU needed).
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/05/14/vllm-quickstart/", "title": "vLLM quickstart", "url": "https://www.gabriel.urdhr.fr/2025/05/14/vllm-quickstart/", "date_published": "2025-05-14T23:11:38+02:00", "date_modified": "2025-05-14T23:11:38+02:00", "tags": ["computer", "machine-learning", "deep-learning", "language-model", "neural-networks", "LLM"], "content_html": "How to quickly use vLLM for LLM inference using CPU.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/03/31/invasion-czechoslovakia/", "title": "Invasion of Czechoslovakia in 1968", "url": "https://www.gabriel.urdhr.fr/2025/03/31/invasion-czechoslovakia/", "date_published": "2025-03-31T00:00:00+02:00", "date_modified": "2025-03-31T00:00:00+02:00", "tags": ["politic", "russia", "europe", "czechoslovakia", "ukraine", "society"], "content_html": "On August 20 1968, Czechoslovakia was invaded by the armies of\nWarsaw Pact.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/03/18/uma-malicious-as/", "title": "Malicious authorization server attack in UMA\u00a02.0", "url": "https://www.gabriel.urdhr.fr/2025/03/18/uma-malicious-as/", "date_published": "2025-03-18T21:23:51+01:00", "date_modified": "2025-03-18T21:23:51+01:00", "tags": ["computer", "protocol", "web", "security", "oauth", "uma"], "content_html": "In a previous post,\nI described a pass-the-permission-ticket vulnerability in UMA\u00a02.0\nin which a malicious UMA resource server\ncould kindly ask a UMA client\nto give it access tokens actually intended for another UMA resource server.\nIn this post,\nI am describing a similar attack when the authorization server is malicious.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/03/18/uma-pass-the-permission-token/", "title": "Pass-the-permission-ticket vulnerability in UMA\u00a02.0", "url": "https://www.gabriel.urdhr.fr/2025/03/18/uma-pass-the-permission-token/", "date_published": "2025-03-18T21:23:50+01:00", "date_modified": "2025-03-18T21:23:50+01:00", "tags": ["computer", "protocol", "web", "security", "oauth", "uma"], "content_html": "In the User-Managed Access (UMA) 2.0 protocol,\na malicious resource server (or a malicious server acting as a resource server)\ncan obtain a requesting party (access) token (RPT)\nintended for another UMA resource server\nfrom a UMA client\nby passing a permission ticket obtained from the target resource server to the UMA client.\nThis can compromise the privacy (confidentiality)\nand integrity of UMA protected resources.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/03/05/trump-post-truth/", "title": "Donald Trump's post-truth alternative facts about Ukraine", "url": "https://www.gabriel.urdhr.fr/2025/03/05/trump-post-truth/", "date_published": "2025-03-05T00:00:00+01:00", "date_modified": "2025-03-05T00:00:00+01:00", "tags": ["politic", "ukraine", "russia", "united-states", "society"], "content_html": "Some notes about Donald Trump's 2025-02-19 weird statements about Ukraine and Volodymyr Zelenskyy.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/01/30/distillation/", "title": "Neural Network Distillation", "url": "https://www.gabriel.urdhr.fr/2025/01/30/distillation/", "date_published": "2025-01-30T00:00:00+01:00", "date_modified": "2025-01-30T00:00:00+01:00", "tags": ["computer", "machine-learning", "deep-learning", "neural-networks"], "content_html": "Overview of neural network distillation\nas done in\n\u201cDistilling the Knowledge in a Neural Network\u201d\n(Hinton et al, 2014).
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/01/27/exposing-services-podman/", "title": "Exposing services in/out Podman containers", "url": "https://www.gabriel.urdhr.fr/2025/01/27/exposing-services-podman/", "date_published": "2025-01-27T00:00:00+01:00", "date_modified": "2025-01-27T00:00:00+01:00", "tags": ["computer", "linux", "system", "podman", "container", "security"], "content_html": "Some more tips for interacting\nwith the namespaces\nof Podman containers.
\n"}, {"id": "http://www.gabriel.urdhr.fr/2025/01/07/transformer-decoder-language-models/", "title": "Transformer-decoder language models", "url": "https://www.gabriel.urdhr.fr/2025/01/07/transformer-decoder-language-models/", "date_published": "2025-01-07T00:00:00+01:00", "date_modified": "2025-09-23T22:22:00+02:00", "tags": ["computer", "machine-learning", "deep-learning", "language-model", "neural-networks", "reinforcement-learning", "LLM"], "content_html": "Some notes on how transformer-decoder language models work,\ntaking GPT-2 as an example,\nand with lots references in order to dig deeper.\nThis is intended both as a a roadmap for understanding on how LLMs work\n(especially the ones using a transformer-decoder architecture)\nand a a summary/recap on the topic.
\n"}]}