Sungkyunkwan University

Seungjoo Kim

Dongho Won

Yunho Lee

Kwangwoo Lee

Sangjoo Park

Younggyo Lee

Provided are an apparatus and method for inputting a graphical password that use representative pictures and elemental pictures of a graphic to form a graphical password and that receive the graphic via a wheel interface and a select button for user authentication. The apparatus includes: an input unit having a wheel interface and a select button; a display for displaying a graphic consisting of representative pictures and elemental pictures, and displaying a changed graphic in response to an input from the wheel interface; a memory for storing a graphical password of a user; and a controller for recognizing, when the select button is pressed, the graphic displayed on the display as a user-input graphical password, and determining whether the input graphical password matches the stored graphical password for user authentication. Thus, it is possible to increase the number of cases for a password using a wheel interface for a higher security level of an embedded system that has a low security level due to a limited type and length of letters input as a password.

Apparatus and method for inputting graphical password using wheel interface in embedded system

A verification method for encrypter operation and an electronic voting verification system using the same, which can verify the operation of the encrypter without having to execute corresponding decryption. In the verification method, the encrypter creates a plurality of ciphertexts corresponding to the plain text and presenting the ciphertexts to a user. The user selects one of the ciphertexts, the encrypter dispenses a certificate where information used by the encrypter during encryption is recorded, in response to the ciphertexts which are not selected by the user; and the user creates a ciphertext in person and verifies whether or not the user-created ciphertext is identical with the user-selected ciphertext. Then, the user can verify the encryption results inside and outside a polling booth.

Verification method for operation of encryption apparatus and its application to electronic voting

A system and method for detecting exposure of an OCSP responder's session private key in a D-OCSP-KIS to verify the status of a user's certificate online are provided. The system includes: a client for requesting certificate status information from the OCSP responder; the OCSP responder for receiving the certificate status information request from the client, sending a response, producing a hash value, and delivering the hash value to a certificate authority (CA) to get a certificate issued; and the CA for receiving the hash value from the OCSP responder and issuing the certificate to the OCSP responder in response to a certificate issue request; wherein the client verifies a digital signature using a hash value contained in the OCSP responder's certificate and the hash value contained in the response, and each client stores a counter value for a hash operation in each verification and recognizes the response as valid when a current counter value is greater than a previous counter value.

Growing community of inventors

Suwon-si, South Korea

Seungjoo Kim