Encoding values by pseudo-random mask
AssigneeNXP B.V.
InventorsWil Michiels, Jan Hoogerbrugge, Philippe Teuwen
Life of this patent
Estimating the term…
Abstract
A method for a keyed cryptographic operation by a cryptographic system mapping an input message to an output message, including: receiving input data for the keyed cryptographic operation; calculating a first mask value based upon the input data; and applying the first mask value to a first intermediate value of the keyed cryptographic operation.
Claims18
A non-transitory machine-readable storage medium encoded with instructions for execution by a keyed cryptographic operation by a cryptographic system mapping an input message to an output message, comprising:
- instructions for receiving input data for the keyed cryptographic operation;
- instructions for calculating a first mask value based upon the input data;
- instructions for applying the first mask value to a first intermediate value of the keyed cryptographic operation;
- and
- instructions for setting a threshold value ϵ, wherein the mask value based upon the input is calculated such that for all values of b:
- |Pa|b−Pa|≤ϵ,
- where Pa|b, is the number of input values for which the masked value equals a given that the first intermediate value equals b divided by the number of values for which the intermediate value equals b, and where Pa is the number of input values for which the masked value equals a divided by the number of input values.
A method of controlling a server that provides an application that implements a keyed cryptographic operation by mapping an input message to an output message, comprising:
- receiving a request from a user for the application that implements a keyed cryptographic operation by mapping an input message to an output message;
- and
- providing the user the application that implements a keyed cryptographic operation by mapping an input message to an output message, wherein the application was created by:
- receiving input data for the keyed cryptographic operation;
- calculating a first mask value based upon the input data;
- and
- applying the first mask value to a first intermediate value of the keyed cryptographic operation,
- wherein the application was further created by setting a threshold value ϵ, wherein the mask value based upon the input is calculated such that for all values of b:
- |Pa|b−Pa|≤ϵ,
- where Pa|b is the number of input values for which the masked value equals a given that the first intermediate value equals b divided by the number of values for which the intermediate value equals b, and where Pa is the number of input values for which the masked value equals a divided by the number of input values.
A method for a keyed cryptographic operation by a cryptographic system mapping an input message to an output message, comprising:
- receiving input data for the keyed cryptographic operation;
- calculating a first mask value based upon the input data;
- applying the first mask value to a first intermediate value of the keyed cryptographic operation;
- and
- setting a threshold value ϵ, wherein the mask value based upon the input is calculated such that for all values of b:
- |Pa|b−Pa|≤ϵ,
- where Pa|b is the number of input values for which the masked value equals a given that the first intermediate value equals b divided by the number of values for which the intermediate value equals b, and where Pa is the number of input values for which the masked value equals a divided by the number of input values.
Dependencies are inferred from the claim text.