[{"name":"SP-231717","title":"New Study on enabling a cryptographic algorithm transition to 256-bits","source":"SA WG3","contact":"Mirko Cano Soveri","contact-id":41957,"tdoctype":"SID new","for":"Approval","abstract":"Objective: This study aims to address key requirements for introducing support for 256-bit symmetric algorithms into the 5G System as well as the coexistence of 128-bit and 256-bit cryptographic algorithms. Considering findings and conclusions from preceding work, the following points should be addressed as part of this study: - Studying key issues and candidate solutions concerning the negotiation (selection) of key sizes between UE and network, including: - Potential risks and impacts to the current system when supporting both 128-bit and 256-bit algorithms in parallel and the adoption of 256-bit algorithms in existing deployments where 128 bits is already supported, e.g. handover scenarios within 5G system - How to prioritise the use of 256-bit algorithms and mitigate bidding-down attacks when negotiating key sizes; - How to ensure 256-bit security is achieved concerning varying levels of support for 256-bit algorithms by different UEs and within the network; potential dependencies in key-length selection of AS and NAS layers - Study the implications and requirements for the key hierarchies to support 256-bit cryptographic algorithms - Study the implications and requirements to AKA procedures. NOTE: coordination with other working groups may be needed during the study.","secretary_remarks":"Revision of SP-231314. This new SID was agreed. Revised to SP-231788.","agenda_item_sort_order":55,"ainumber":"6.4.3","ainame":"SA WG3 and SA WG3-LI New Release 19 Study Item Descriptions","tdoc_agenda_sort_order":10940,"status":"revised","reservation_date":"2023-12-14 08:29:33","uploaded":"2023-12-15 16:01:10","revisionof":"SP-231314","revisedto":"SP-231788","release":"","crspec":"","crspecversion":"","workitem":"","crnumber":"","crrevision":"","crcategory":"","tsg_crp":"","lsreplyto":"","lsto":"","Cc":"","lsoriginalls":"","lsreply":"","link":"https:\/\/www.3gpp.org\/ftp\/TSG_SA\/TSG_SA\/TSGS_102_Edinburgh_2023-12\/Docs\/SP-231717.zip","group":"SP","meeting":"SP-102","year":2023,"uicc_affected":"","me_affected":"","ran_affected":"","cn_affected":"","clauses_affected":"","crsinpack":null,"crsinpacknumber":0}]