Disclosed herein is an apparatus for calculating a cryptographic component R.sup.2 mod n for a cryptographic function, where n is a modulo number and R is a constant greater than n. The apparatus comprises a processor configured to set a start value to be equal to R mod n, perform b iterations of a shift and subtract operation on the start value to produce a base value, wherein the start value is set to be equal to the base value after each iteration, set a multiplication operand to be equal to the base value, and perform k iterations of a Montgomery modular multiplication of the multiplication operand with the multiplication operand to produce an intermediate result, wherein the multiplication operand is set to be equal to the intermediate result after each iteration, wherein the shift and subtract operation comprises determining a shifted start value which is equivalent to the start value multiplied by two, and subtracting n from the shifted start value if the shifted start value is greater than or equal to n.

Disclosed herein is an apparatus for calculating a cryptographic component R.sup.2 mod n for a cryptographic function, where n is a modulo number and R is a constant greater than n. The apparatus comprises a processor configured to set a start value to be equal to R mod n, perform b iterations of a shift and subtract operation on the start value to produce a base value, wherein the start value is set to be equal to the base value after each iteration, set a multiplication operand to be equal to the base value, and perform k iterations of a Montgomery modular multiplication of the multiplication operand with the multiplication operand to produce an intermediate result, wherein the multiplication operand is set to be equal to the intermediate result after each iteration, wherein the shift and subtract operation comprises determining a shifted start value which is equivalent to the start value multiplied by two, and subtracting n from the shifted start value if the shifted start value is greater than or equal to n.

A communication system includes a mobile device and an apparatus. The apparatus obtains unique data from the mobile device by using a common key while the common key is stored in the mobile device, generates a unique key by using the obtained unique data, stores the generated unique key as a service key in the apparatus, and transmits the generated unique key to the mobile device. When the mobile device receives the unique key from the apparatus while the common key is stored in the mobile device, the mobile device rewrites a service key stored in the mobile device from the common key to the unique key.

The present invention reduces security risks while improving the convenience of utilization control technology of an usage target object. A use permit issuance device (1): stores, for each user, authentication data and an authentication method in association with identification information of one or more users and upon receipt of a use permit issuance request from a setting terminal (5), issues a use permit to generate a signature, and identifies the authentication data associated with the user identification information and the authentication method included in the issuance request, and notifies the setting terminal (5) of setting information including the use permit, the signature and the authentication data. The setting terminal (5) registers the setting information in a use permit notification device (4). The use permit notification device (4) acquires authentication data from a user, and transmits the use permit and the signature of the setting information including the authentication data to a utilization control device (3). The utilization control device (3) verifies the signature, and if the signature verification is established, unlocks use restrictions of a usage target object when a use condition included in the use permit being satisfied.

A system includes an authenticated encryption layer comprising logic configured to encrypt data received at the authenticated encryption layer from an authorized application at a source node. The data is encrypted using a first key to obtain first encrypted data. The logic is configured to encrypt the first encrypted data using a second key to obtain second encrypted data and generate a watermark for the first encrypted data and/or a watermark for the second encrypted data. The logic is configured to generate a watermark token for the first encrypted data and/or a watermark token for the second encrypted data.

Among four secure computation nodes, one secure computation node is selected as a receiving node. Two of three remaining secure computation nodes among the four secure computation nodes are operated as resharing nodes, and a remaining secure computation node is operated as a verifying node. The resharing node(s) performs a mini-shuffle for resharing share(s) held therein by using a permutation that the receiving node does not know and transmits a result(s) of the mini-shuffle to the receiving node. The verifying node computes data to verify the result(s) of the mini-shuffle performed by the resharing node(s) by using a permutation that the receiving node does not know and transmits the data to the receiving node. Shuffling of shares is achieved by repeatedly performing a round as described above so that each of the four secure computation nodes is selected as the receiving node at least once.

A secret key estimation device is provided for determining an estimate of at least one secret key used during a number of executions of a cryptographic function used by at least one cryptographic algorithm. The number of executions of the cryptographic function is at least equal to two. The secret key estimation device comprises an analysis unit for determining a plurality of sets of leakage traces from a side-channel information acquired during the number of executions of the cryptographic function. Each set of leakage traces corresponds to an execution of the cryptographic function and comprising at least one leakage trace. The secret key estimation device further comprises a processing unit configured to determine a statistical distribution of the acquired plurality of sets of leakage traces. The statistical distribution is dependent on a leakage function, the leakage function being represented in a basis of functions by a set of real values. The secret key estimation device is configured to determine the secret key from the statistical distribution of the plurality of sets of leakage traces using an estimation algorithm according to the maximization of a performance metric.

A system for applying fingerprinting/watermarking of consumer data, and analyzing “wild files” of consumer data to assign a guilt score for a particular party who may have leaked the data, allows the owner of data sources (“Data Owners”) to identify and assert ownership of textual data that has been distributed outside of their firewall in the clear (i.e., without encryption), either intentionally or unintentionally, and assign guilt to parties misusing the data. The system can be used by Data Owners who transmit, lease, or sell data to individuals or organizations (“Trusted Third Parties” or “TTPs”) to recognize and assert ownership of their data in the case where one or more TTPs leaks the data (the leaked file is defined as a “Leaked Subset”) into the hands of others (“Bad Actors”) who either knowingly or unknowingly use the data illegally.

A system for applying fingerprinting/watermarking of consumer data, and analyzing “wild files” of consumer data to assign a guilt score for a particular party who may have leaked the data, allows the owner of data sources (“Data Owners”) to identify and assert ownership of textual data that has been distributed outside of their firewall in the clear (i.e., without encryption), either intentionally or unintentionally, and assign guilt to parties misusing the data. The system can be used by Data Owners who transmit, lease, or sell data to individuals or organizations (“Trusted Third Parties” or “TTPs”) to recognize and assert ownership of their data in the case where one or more TTPs leaks the data (the leaked file is defined as a “Leaked Subset”) into the hands of others (“Bad Actors”) who either knowingly or unknowingly use the data illegally.

Method for the secure execution of programs (smart contracts) implemented between a first wallet node (WN) (WN1) and a second wallet node (WN2), at least the second WN being implemented in an enclave of a processor, and the WNs being capable of executing programs designated in the messages that reach them, the method comprising the following steps: a) sending by WN1 to WN2 of a pre-message; b1) in response to this pre-message, execution in the enclave of a first program (WNRoT); b2) generation by the enclave of a certificate of authenticity of said first program and of the integrity of its execution; b3) sending said certificate to WN1; c) verification by WN1 of said certificate; d) in the event of successful verification, sending by WN1 to WN2 of a message intended to trigger the execution of a given program in WN2, and e) execution of said program in WN2.