| 摘要 |
This report is devoted to measuring the resistance of data encodings to reverse engineering. We introduce a measure of encoding resistance in an en- coded world as a measure of uncertainty: specifically, the number of possibl e or 'real' worlds which can correspond to the observable encoded world. An attacker observing only operations in encoded world and inputs to encoded world (i.e., all encoded input data) can not distinguish between any of 'rea l' worlds. Thus the larger the number of corresponding 'real' worlds, the more uncertainty and resistance the encoding has. It is important to note that such measures characterize the resistance of encoding to an arbitrary attack which only uses information from the encoded world. We present estimates of resistance of linear, residue and mixed encodin gs for addition and multiplication and find that maximal resistance is achieved for mixed encoding. We show that there exist more resistant schemes for performing multiplication in mixed encodings. We estimate resistance of computation of arbitrary multivariate polyno- mials in mixed encoding and proposed several ways to increase the resistance of arbitrary computation in mixed encoding.
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