랜덤선형부호의 복호화 문제와 그의 암호학적 응용

  • Published : 2015.05.29

Abstract

오류정정부호는 정보를 부호화하여 데이터 전송 과정에서 발생하는 에러를 감소시킴으로써 통신 신뢰성을 향상시킨다. 이에 따라 에러를 효율적으로 검출 및 정정할 수 있는 부호(code)가 필수적이다. 반면 암호에서는 중요한 정보를 은닉하기 위한 목적으로 비밀정보에 인위적으로 오류를 주입한다. 따라서 기밀성을 유지하기 위해서는 위와는 반대로 오류정정이 어려운 부호를 필요로 한다. 본고에서는 오류정정의 어려움으로 메시지의 비밀성은 유지되고, 덧문(trapdoor)을 가지고 있어 비밀정보가 있을 때는 메시지가 복구되는 암호학적 응용이 가능한 랜덤선형부호의 복호화 문제와 그의 응용에 대해 살펴보고자 한다. 이 문제는 암호학에서 LPN/LWE 문제로 불리며, 최근 LPN문제의 일반화된 문제인 LWE문제가 Regev에 의해 소개되면서 동형암호, 기능암호 등에 광범위하게 응용되고 있다.

Keywords

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