发明授权
US08175265B2 Systems and methods for implementing block cipher algorithms on attacker-controlled systems
有权
用于在攻击者控制的系统上实现块密码算法的系统和方法
- 专利标题: Systems and methods for implementing block cipher algorithms on attacker-controlled systems
- 专利标题(中): 用于在攻击者控制的系统上实现块密码算法的系统和方法
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申请号: US12203120申请日: 2008-09-02
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公开(公告)号: US08175265B2公开(公告)日: 2012-05-08
- 发明人: Mathieu Ciet , Augustin J. Farrugia , Filip Toma Paun
- 申请人: Mathieu Ciet , Augustin J. Farrugia , Filip Toma Paun
- 申请人地址: US CA Cupertino
- 专利权人: Apple Inc.
- 当前专利权人: Apple Inc.
- 当前专利权人地址: US CA Cupertino
- 代理机构: Novak Druce + Quigg LLP
- 主分类号: H04L9/00
- IPC分类号: H04L9/00
摘要:
Systems and methods for an implementation of block cipher algorithms (e.g., AES) use lookup tables to obscure key information, increasing difficulty for those with privileged access to a system performing the AES algorithm to obtain such key information. The implementation encodes round key information into a first plurality of tables (T1), which when used for lookup operations also complete SubBytes operations, and output state in an encoded format. A Shiftrows operation is performed arithmetically on the state output from the T1 table lookups. A second plurality of tables (T2) are used to perform a polynomial multiplication portion of MixColumns to state from Shiftrows, and an XOR portion of MixColumns is performed arithmetically on the columns outputted from using the T2 tables. Encoding from the T1 tables is made to match a decoding built into the T2 tables. Subsets of the T1 tables use the same T2 tables, reducing a memory footprint for the T2 tables. Multiple AES keys can be embedded in different sets of T1 tables that encode for the same set of T2 tables.
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