{"version": "https://jsonfeed.org/version/1", "title": "/dev/posts/ - Tag index - elliptic-curve", "home_page_url": "https://www.gabriel.urdhr.fr", "feed_url": "/tags/elliptic-curve/feed.json", "items": [{"id": "http://www.gabriel.urdhr.fr/2026/06/27/ecdsa-jwt-malleability/", "title": "Malleability of ECDSA (and DSA) signatures, JWTs, etc.", "url": "https://www.gabriel.urdhr.fr/2026/06/27/ecdsa-jwt-malleability/", "date_published": "2026-06-27T00:00:00+02:00", "date_modified": "2026-06-27T00:00:00+02:00", "tags": ["computer", "security", "cryptography", "elliptic-curve", "jwt", "ecdsa"], "content_html": "<p>This blog posts explains that ECDSA and DSA signatures are malleable,\nthat JWTs can be malleable as well\nand how this can be used to bypass some broken implementations\nof JWT deny lists\n(for revocation of JWTs or anti-replay protection).</p>\n"}, {"id": "http://www.gabriel.urdhr.fr/2021/10/19/diffie-hellman-intro/", "title": "Introduction to the Diffie-Hellman key exchange", "url": "https://www.gabriel.urdhr.fr/2021/10/19/diffie-hellman-intro/", "date_published": "2021-10-19T00:00:00+02:00", "date_modified": "2021-10-19T00:00:00+02:00", "tags": ["computer", "network", "cryptography", "tls", "diffie-hellman", "elliptic-curve"], "content_html": "<p>The Diffie-Hellman (DH) key exchange (and variants thereof) is widely used\nin many protocols\n(such as TLS, SSH, IKE (IPSec), Signal, etc.)\nto bootstrap some symmetric key material\nwhich may then be used to secure communication channel between two parties.\nThis introduction\nfocuses on the different ways the DH key exchange\nis used in practice\nin several protocols (especially TLS)\nand the impact of these different approaches on the security.\nThis is intended as a prelude for the upcoming <a href=\"https://www.gabriel.urdhr.fr/2021/11/30/tls1.2-intro/\">next episodes</a>\nabout how TLS works.</p>\n"}]}