★★★ ＜知的財産翻訳検定＞答案用紙 ★★★
==================================================================科目：電気・電子工学

氏

名：坂本礼子==================================================================
What is claimed is:
1. An encryption communication apparatus comprising:an encryption recording means including:an error-correction encoding means that performs error-correction encoding byadding redundancy to inputted data;
an interleaving means that sorts the data outputted from the error-correction
encoding means by a predetermined bit number according to a previously specified rule,and outputs the sorted data; andan encoding means that encodes the outputted data from the interleaving means
so as to keep content of the outputted data from the interleaving means secret; andan encryption reproducing means including:a decoding means that decodes inputted data that is data outputted from theencryption recording means reproduced from any recording medium;a de-interleaving means that sorts, so as to restore an order of the data sorted by
the interleaving means, the data outputted from the decoding means by apredetermined bit number according to a previously specified rule, and outputs the data
sorted by the de-interleaving means; andan error-correction decoding means that corrects an error in the data outputtedfrom the de-interleaving means, based on the redundancy added by the error-correction
encoding means.
2. The encryption communication apparatus according to Claim 1, whereineach means included in the encryption recording means and each means includedin the encryption reproducing means are given information for operation fromrespective key information generating means.

In the encryption reproducing means, the data outputted from the encryption
recording means is decoded by the decoding means 5. Consecutive errors in the data
outputted from the decoding means 5 that have been caused by errors in the data
generated in the given recording medium are converted to random pseudo-errors by thede-interleaving means 6.

FIGs. 3A, 3B, and 3C illustrate the above operation.

Assuming that the encoding means 3 and decoding means 5 are block ciphers, whenerrors are generated in the data inputted to the decoding means 5 in the process of-1-reproduction from the recording medium, consecutive errors are generated in the blocks
having errors during inputted as shown by a block Bi in a reference numeral 13 in FIG
3A.

Also assuming that the de-interleaving means 6 is such that, in a memory

structure by a matrix as shown by a reference numeral 14 in FIG. 3B, sequentiallywriting in a column direction of a row is performed when writing and sequentiallyreading in a row direction of a column is performed when reading, the block Bi having
the error is written to an i-th row in the memory of the de-interleaving means 6, and thedata in the block Bi having the error appears dispersed in an i-th bit of each column
when reading (Pj, i 16 in Pj15 in FIG. 3C). As described above, in blocks having
consecutive errors in the data outputted from the decoding means 5 are dispersed by thede-interleaving means 6, and the errors in the data outputted from the de-interleaving
means 6 appear almost randomly.

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