BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Laboratoire de Mathématiques de Versailles - ECPv6.16.2//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:Laboratoire de Mathématiques de Versailles
X-ORIGINAL-URL:https://lmv.math.cnrs.fr
X-WR-CALDESC:Évènements pour Laboratoire de Mathématiques de Versailles
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Europe/Paris
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20210328T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20211031T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20220327T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20221030T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20230326T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20231029T010000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220210T110000
DTEND;TZID=Europe/Paris:20220210T120000
DTSTAMP:20260518T165851
CREATED:20220131T121449Z
LAST-MODIFIED:20220211T133509Z
UID:9921-1644490800-1644494400@lmv.math.cnrs.fr
SUMMARY:CRYPTO : Yann Rotella (UVSQ) : Cryptanalyse des algorithmes GEA-1 et GEA-2 pour la communication GPRS
DESCRIPTION:Dans cette présentation\, nous présenterons l’article publié à Eurocrypt 2021 [BDLLRRRS21]. Nous montrerons comment retrouver l’état interne dans ces deux chiffrements\, encore utilisés dans la communication 2G. Notre attaque nécessite 44 GB de mémoire et peut se faire avec un nombre réduit de couples clairs / chiffrés\, en utilisant principalement l’interaction entre deux registres de l’état interne. De plus\, nous montrerons que cette interaction est peu probable et que cela indique que la faiblesse aurait pu être introduite intentionnellement. \nNous montrerons aussi comment attaquer GEA-2\, en combinant plusieurs techniques de cryptanalyse. \nhttps://link.springer.com/chapter/10.1007/978-3-030-77886-6_6 \nhttps://eprint.iacr.org/2021/819.pdf \n  \nLe séminaire aura lieu en hybride (via Zoom). 
URL:https://lmv.math.cnrs.fr/evenenement/crypto-yann-rotella-uvsq-cryptanalysis-of-the-gprs-encryption-algorithms-gea-1-and-gea-2/
LOCATION:Bâtiment Descartes\, salle 301
CATEGORIES:Séminaire CRYPTO
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20220224T111000
DTEND;TZID=Europe/Paris:20220224T123000
DTSTAMP:20260518T165851
CREATED:20220216T150035Z
LAST-MODIFIED:20220303T094358Z
UID:9994-1645701000-1645705800@lmv.math.cnrs.fr
SUMMARY:CRYPTO : Pierre Galissant (UVSQ) : Resisting Key-Extraction and Code-Compression: a Secure Implementation of the HFE Signature Scheme in the White-Box Model
DESCRIPTION:Cryptography is increasingly deployed in applications running on open devices in which the software is extremely vulnerable to attacks\, since the attacker has complete control over the execution platform and the software implementation itself. This creates a challenge for cryptography: design implementations of cryptographic algorithms that are secure\, not only in the black-box model\, but also in this attack context that is referred to as the white-box adversary model. Moreover\, emerging applications such as mobile payment\, mobile contract signing or blockchain-based technologies have created a need for white-box implementations of public-key cryptography\, and especially of signature algorithms. \nHowever\, while many attempts were made to construct white-box implementations of block-ciphers\, almost no white-box implementations have been published for what concerns asymmetric schemes. We present here a concrete white-box implementation of the well-known HFE signature algorithm for a specific set of internal polynomials. For a security level $2^{80}$\, the public key size is approximately 62.5 MB and the white-box implementation of the signature algorithm has a size approximately 256 GB. \nThe talk will be based on joint work with Louis Goubin. A preprint is available here :  https://eprint.iacr.org/2022/138
URL:https://lmv.math.cnrs.fr/evenenement/crypto-pierre-galissant-uvsq-resisting-key-extraction-and-code-compression-a-secure-implementation-of-the-hfe-signature-scheme-in-the-white-box-model/
LOCATION:Bâtiment Descartes\, salle 301
CATEGORIES:Séminaire CRYPTO
END:VEVENT
END:VCALENDAR