• Title/Summary/Keyword: 치환 암호

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Design of the Covered Address Generation using the Super Increasing Sequence in Wireless Networks (무선 네트워크에서의 초증가 수열을 통한 주소 은닉 기법 설계)

  • Choun, Jun-Ho;Kim, Sung-Chan;Jang, Kun-Won;Do, Kyung-Hwa;Jun, Moon-Seog
    • The KIPS Transactions:PartC
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    • v.14C no.5
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    • pp.411-416
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    • 2007
  • The General security method of wireless network provides a confidentiality of communication contents based on the cryptographic stability against a malicious host. However, this method exposes the logical and physical addresses of both sender and receiver, so transmission volume and identification of both may be exposed although concealing that content. Covered address scheme that this paper proposes generates an address to which knapsack problem using super increasing sequence is applied, and replaces the addresses of sender and receiver with addresses from super increasing sequence. Also, proposed method changes frequently secret addresses, so a malicious user cannot watch a target system or try to attack the specific host. Proposed method also changes continuously a host address that attacker takes aim at. Accordingly, an attacker who tries to use DDoS attack cannot decide the specific target system.

The Optimal Normal Elements for Massey-Omura Multiplier (Massey-Omura 승산기를 위한 최적 정규원소)

  • 김창규
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.14 no.3
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    • pp.41-48
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    • 2004
  • Finite field multiplication and division are important arithmetic operation in error-correcting codes and cryptosystems. The elements of the finite field GF($2^m$) are represented by bases with a primitive polynomial of degree m over GF(2). We can be easily realized for multiplication or computing multiplicative inverse in GF($2^m$) based on a normal basis representation. The number of product terms of logic function determines a complexity of the Messay-Omura multiplier. A normal basis exists for every finite field. It is not easy to find the optimal normal element for a given primitive polynomial. In this paper, the generating method of normal basis is investigated. The normal bases whose product terms are less than other bases for multiplication in GF($2^m$) are found. For each primitive polynomial, a list of normal elements and number of product terms are presented.