Abstract:
A visibly verifiable key exchange apparatus, a visibly verifiable key exchange system using a reliable authentication agent, and a method and recording medium thereof are provided to secure the anonymity of a user ID by using a picture of the user as the user ID. A visibly verifiable key exchange method includes the steps of: transmitting an encrypted picture of a user to a terminal of the other user(310), and receiving the encrypted picture of the other user from the terminal of the other user(320); and if the user and the other user check the picture of a counterpart(330), applying a session key which is generated by using the pictures of the user and the other user to the communication between the terminal of the user and the terminal of the other user(340). The communication applying step includes the steps of: displaying the picture of the counterpart on the terminal of the user and the terminal of the other user; and if a check button is pushed, deciding that the user and the other user check the picture of the counterpart.
Abstract:
암호화된 데이터베이스 검색 방법 및 그 시스템이 개시된다. 본 발명은 인증된 사용자가 문서 및 상기 문서에 대한 대표 키워드를 입력하면, 상기 문서를 문서암호용 키로 암호화하고 상기 대표 키워드를 검색키로 암호화하여 인덱스를 생성하며, 상기 암호화된 문서 및 상기 인덱스를 상기 서버에 전송하는 단계, 임의의 클라이언트에서 인증된 사용자가 검색할 문서에 대한 키워드를 입력하면, 상기 입력된 키워드와 상기 사용자의 검색키를 이용한 트랩도어를 생성하여 상기 서버에 질의하는 단계 및 상기 서버에서 상기 트랩도어 및 상기 서버에 저장된 인덱스를 이용하여 암호화된 문서를 검색하고 검색된 문서를 상기 클라이언트에 전송하는 단계를 포함한다. 본 발명에 의하면, 데이터베이스에 암호화 기법을 적용하면서 동시에 효율적인 검색을 가능하게 하고, 정보의 유출을 막아 정보의 오남용을 막을 뿐 아니라 계층적인 접근 권한을 둘 수 있다.
Abstract:
A visibly verifiable key exchange apparatus, a visibly verifiable key exchange system using a reliable authentication agent, and a method and recording medium thereof are provided to secure the anonymity of a user ID by using a picture of the user as the user ID. A visibly verifiable key exchange method includes the steps of: transmitting an encrypted picture of a user to a terminal of the other user(310), and receiving the encrypted picture of the other user from the terminal of the other user(320); and if the user and the other user check the picture of a counterpart(330), applying a session key which is generated by using the pictures of the user and the other user to the communication between the terminal of the user and the terminal of the other user(340). The communication applying step includes the steps of: displaying the picture of the counterpart on the terminal of the user and the terminal of the other user; and if a check button is pushed, deciding that the user and the other user check the picture of the counterpart.
Abstract:
A method for searching information from an encrypted database and a system thereof are provided to perform systematic information management and efficient information search via hierarchical database access rights as well as to prevent information from being illegally used or abused. A method for searching information from an encrypted database comprises the following several steps. If an authenticated user inputs a document and a representative keyword for the document, a client encrypts the inputted document via a document encryption key, encrypts the inputted representative keyword via a search key, generates an index, and transmits the encrypted document and index to a server(210). The client determines whether a user authenticated in an arbitrary client inputs a keyword for a document to be searched(220). If so, the client generates a trapdoor by using the inputted keyword and the search key of the user, and sends a query to a server(225). The server searches for the encrypted document by using the trapdoor and the index and transmits the searched document to the client(230).