发明名称 METHODS AND APPARATUS FOR EFFICIENT COMPUTATION OF ONE-WAY CHAINS IN CRYPTOGRAPHIC APPLICATIONS
摘要 Techniques are disclosed for efficient computation of consecutive values of one-way chains and other one-way graphs in cryptographic applications. The one-way chain or graph may be a chain of length s having positions i=1, 2, . . . s each having a corresponding value vi associated therewith, wherein the value vi is given by vi=h (vi+1), for a given hash function or other one-way function h. An initial distribution of helper values may be stored for the one-way chain of length s, e.g., at positions given by i=2j for 0≦j≦log2 s. A given one of the output values vi at a current position in the one-way chain may be computed utilizing a first helper value previously stored for another position in the one-way chain between the current position and an endpoint of the chain. After computation of the given output value, the positions of the helper values are adjusted so as to facilitate computation of subsequent output values. Advantageously, a storage-computation product associated with generation of the output values of the one-way chain has a complexity O(log s)2).
申请公布号 US2015154408(A1) 申请公布日期 2015.06.04
申请号 US201514622104 申请日期 2015.02.13
申请人 Jakobsson Bjorn Markus 发明人 Jakobsson Bjorn Markus
分类号 G06F21/60;H04L9/32 主分类号 G06F21/60
代理机构 代理人
主权项 1. A method implemented by a processor, the processor being coupled to a memory, the memory having a designated amount of storage available for storing values of a one-way chain, the designated amount of available storage being less than that required to store simultaneously all of the values of the one-way chain, the method comprising the steps of: storing in the memory a subset of the values of the one-way chain as helper values for facilitating computation of other values of the one-way chain not in the subset; utilizing one of the values in the subset of values to compute one of the other values of the one-way chain not in the subset; generating a cryptographic output determined by the computed value not in the subset; and updating the stored subset of values of the one-way chain so as to replace at least one of the helper values with a new helper value not previously part of the subset.
地址 Mountain View CA US
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