{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9681292","patent":{"patent_number":"US-9681292","title":"Method for handling ciphering keys in a mobile station","assignee":null,"inventors":[],"filing_date":"2010-08-17T00:00:00.000Z","publication_date":"2017-06-13T00:00:00.000Z","cpc_codes":["H04W","H04W","H04W","H04W","H04W","H04W","H04L"],"num_claims":22,"abstract":"Techniques for handling ciphering keys in a mobile station comprising a mobile equipment (ME) and a Universal Subscriber Identity Module (USIM) are disclosed. An example method includes obtaining a UMTS cipher key (CK), integrity key (IK), and ciphering key sequence number (CKSN) from the USIM, deriving a 128-bit ciphering key (Kc-128) from the CK and the IK, and storing the Kc-128 and the CKSN on the mobile equipment, separate from the USIM. The stored CKSN is associated with the stored Kc-128, so that the Kc-128's correspondence to the most current UMTS security context can be tracked. This example method applies to the generation and storage of a 128-bit ciphering key for either the packet-switched or circuit-switched domains. A corresponding user equipment apparatus is also disclosed."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Method for handling ciphering keys in a mobile station","description":"Techniques for handling ciphering keys in a mobile station comprising a mobile equipment (ME) and a Universal Subscriber Identity Module (USIM) are disclosed. An example method includes obtaining a UM","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9681292","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-9681292","citation_suggestion":"Patentable. \"Method for handling ciphering keys in a mobile station\" (US-9681292). https://patentable.app/patents/US-9681292","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9681292","json":"https://patentable.app/api/llm-context/US-9681292","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T08:20:03.892Z"}