On the security of TLS renegotiation

The Transport Layer Security (TLS) protocol is the most widely used security protocol on the Internet. It supports negotiation of a wide variety of cryptographic primitives through different cipher suites, various modes of client authentication, and additional features such as renegotiation. Despite its widespread use, only recently has the full TLS protocol been proven secure, and only the core cryptographic protocol with no additional features. These additional features have been the cause of several practical attacks on TLS. In 2009, Ray and Dispensa demonstrated how TLS renegotiation allows an attacker to splice together its own session with that of a victim, resulting in a man-in-the-middle attack on TLS-reliant applications such as HTTP. TLS was subsequently patched with two defence mechanisms for protection against this attack. We present the first formal treatment of renegotiation in secure channel establishment protocols. We add optional renegotiation to the authenticated and confidential channel establishment model of Jager et al., an adaptation of the Bellare--Rogaway authenticated key exchange model. We describe the attack of Ray and Dispensa on TLS within our model. We show generically that the proposed fixes for TLS offer good protection against renegotiation attacks, and give a simple new countermeasure that provides renegotiation security for TLS even in the face of stronger adversaries.

Teología, 1982, Tomo XIX nº 040 (número completo)

Para mejorar entender la “Dives in Misericordia” / Eduardo Briancesco -- Renovación jurídica de la vida consagrada. Principios y líneas generales / Emilio Barcelón -- El amor al dinero: “Idolatría y Raíz de todos los Males”. Lecciones de patrística para los problemas de hoy / Carmelo Giaquinta -- Dos dramas quechuas sobre el Patrocinio que la Santísima Virgen María dispensa a los pecadores: “el pobre más rico” y “Usca Paucar” / Alberto Espezel – Francisco Blanco Martín -- Crónica de la Facultad -- Notas bibliográficas -- Libros recibidos -- índice volumen XIX

Proceso sobre rato y no consumado : fase inicial diocesana

Resumen: El proceso para conceder la gracia apostólica de la dispensa del matrimonio rato y no consumado tiene una fase diocesana. La misma ha sido presentada por el autor en forma de taller práctico y forma parte del curso práctico Procesos matrimoniales, hoy, dictado por la Rota Romana en su visita a la Facultad de Derecho Canónico en Buenos Aires.