A cipher processing configuration, of which the resistance against various attacks is improved, having a high security level is realized. In a cipher processing configuration in which a nonlinear transformation process and a linear transformation process are repeatedly performed for state data formed from a plurality of elements, a linear transformation unit performs a matrix operation applying a quasi-MDS matrix and a substitution process. As the substitution process, a substitution process is performed which satisfies the following (Condition 1) and (Condition A). (Condition 1) According to the substitution process of the substitution unit for the input X, each column element of the output Y is configured by elements of four mutually-different columns of the input X (Condition A) In a case where the substitution process performed by the substitution unit for the input X is repeatedly performed continuously twice, each column element of the output Y is configured by elements of three or more mutually-different columns of the input X.

A computer implement format preservation based masking system and method is provided. The system obtains a first set of letters and a private key, and encrypts the first set of letters to obtain an encrypted letters list using the first set and private key. The encrypted letters list comprises a set of encrypted letters. A dynamic map is generated based on the encrypted letters, which includes one or more keys, each key being specific to a letter in the first set letters. A position of each of maskable letters in a second set of letters is calculated using the dynamic map, and performs masking of the maskable letters based on the position of each of the maskable letters to obtain masked data using the dynamic map.

A computer implement format preservation based masking system and method is provided. The system obtains a first set of letters and a private key, and encrypts the first set of letters to obtain an encrypted letters list using the first set and private key. The encrypted letters list comprises a set of encrypted letters. A dynamic map is generated based on the encrypted letters, which includes one or more keys, each key being specific to a letter in the first set letters. A position of each of maskable letters in a second set of letters is calculated using the dynamic map, and performs masking of the maskable letters based on the position of each of the maskable letters to obtain masked data using the dynamic map.

A system, method, and computer-readable medium for challenge-response authentication are provided. A plurality of codes is received over a communication network based on input provided by way of a user interface displaying a plurality of images. An alphanumeric string is generated based on the received plurality of codes and based on a table that associates each one of the plurality of codes with a respective one of the plurality of images and with a respective one of a plurality of alphanumeric characters. A determination is made as to whether to grant authorization based on whether the generated alphanumeric string matches an alphanumeric user identifier stored in a memory device in association with a user.

A system, method, and computer-readable medium for challenge-response authentication are provided. A plurality of codes is received over a communication network based on input provided by way of a user interface displaying a plurality of images. An alphanumeric string is generated based on the received plurality of codes and based on a table that associates each one of the plurality of codes with a respective one of the plurality of images and with a respective one of a plurality of alphanumeric characters. A determination is made as to whether to grant authorization based on whether the generated alphanumeric string matches an alphanumeric user identifier stored in a memory device in association with a user.

There are several approaches to encrypting circuits: combination logic encryption, encrypted gate topologies, transmission gate topologies, and key expansion of gate topologies. Each of these may encrypt a circuit with certain advantages in delay and power consumption.

There are several approaches to encrypting circuits: combination logic encryption, encrypted gate topologies, transmission gate topologies, and key expansion of gate topologies. Each of these may encrypt a circuit with certain advantages in delay and power consumption.

A system, method, and computer-readable medium for challenge-response authentication are provided. A plurality of codes is received over a communication network based on input provided by way of a user interface displaying a plurality of images. An alphanumeric string is generated based on the received plurality of codes and based on a table that associates each one of the plurality of codes with a respective one of the plurality of images and with a respective one of a plurality of alphanumeric characters. A determination is made as to whether to grant authorization based on whether the generated alphanumeric string matches an alphanumeric user identifier stored in a memory device in association with a user.

A system, method, and computer-readable medium for challenge-response authentication are provided. A plurality of codes is received over a communication network based on input provided by way of a user interface displaying a plurality of images. An alphanumeric string is generated based on the received plurality of codes and based on a table that associates each one of the plurality of codes with a respective one of the plurality of images and with a respective one of a plurality of alphanumeric characters. A determination is made as to whether to grant authorization based on whether the generated alphanumeric string matches an alphanumeric user identifier stored in a memory device in association with a user.

In a general aspect, a method can include: transmitting, to a terminal of the user via the server, an impenetrable program that can configure the terminal to display, on a display screen of the terminal, an image of a keypad having a randomly defined key distribution, the image including frames that are separately unintelligible for the user and are consecutively displayed at a rate suitable for using the persistence of the visual system of the user; executing the program via the terminal; gathering, via the terminal, positions of the display screen, designated by the user in relation to the displayed image of the keypad; transmitting, to the server via the terminal, the positions designated by the user, and verifying, via the server, the designated positions, the user being authenticated if the designated positions in the displayed image correspond to a secret authentication code of the user.