发明名称 |
METHOD FOR ARBITRARY-PRECISION DIVISION OR MODULAR REDUCTION |
摘要 |
A method in a portable data carrier for executing a cryptographic operation on security-relevant data comprises a step of determining a remainder (r) of a dividend (a) modulo a divisor (b). In so doing, the remainder (r) is determined iteratively by means of a division device of the data carrier. In each iteration there is carried out a Montgomery multiplication with the divisor (b) as the modulus and an additive linkage of an output value of the Montgomery multiplication with a coefficient (ai) derived from the dividend (a) and associated with the respective iteration. The Montgomery multiplication is carried out here by means of a multiplication device of the data carrier, preferably a corresponding coprocessor. The Montgomery multiplication of a subsequent iteration receives a result of a preceding iteration as an input value.
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申请公布号 |
US2013236006(A1) |
申请公布日期 |
2013.09.12 |
申请号 |
US201113885878 |
申请日期 |
2011.11.16 |
申请人 |
BOCKES MARKUS;PULKUS JURGEN;GIESECKE & DEVRIENT GMBH |
发明人 |
BOCKES MARKUS;PULKUS JURGEN |
分类号 |
H04L9/28 |
主分类号 |
H04L9/28 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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