Converting a boolean masked value to an arithmetically masked value for cryptographic operations

A method comprising:

• performing a cryptographic operation with a Boolean operation;
• receiving an indication that the cryptographic operation has switched from using the Boolean operation to an arithmetic operation;
• in response to receiving the indication, receiving a first input share value, a second input share value, and a third input share value;
• converting the first input share value to a summation or a subtraction between an input value and a combination of the second input share value and the third input share value;
• generating a random number value;
• combining the random number value with the second input share value and the third input share value to generate a combined value;
• generating, by a processing device, a first output share value based on a combination of the converted first input share value, the combined value, and additional random number values;
• and
• performing the cryptographic operation with the arithmetic operation by using the first output share value.

A non-transitory computer readable medium including data that, when accessed by a processing device, cause the processing device to perform operations comprising:

• performing a cryptographic operation with a Boolean operation;
• receiving an indication that the cryptographic operation has switched from using the Boolean operation to an arithmetic operation;
• in response to receiving the indication, receiving a first input share value, a second input share value, and a third input share value;
• converting the first input share value to a summation or a subtraction between an input value and a combination of the second input share value and the third input share value;
• generating a random number value;
• combining the random number value with the second input share value and the third input share value to generate a combined value;
• generating a first output share value based on a combination of the converted first share value, the combined value, and additional random number values;
• and
• performing the cryptographic operation with the arithmetic operation by using the first output share value.