Secure two-party data comparison method and apparatus based on scale transformation

A secure two-party data comparison apparatus based on scale transformation, comprising:

• a computation requesting party, a first participant node, and a second participant node, wherein the first participant node holds first private data, and the second participant node holds second private data;
• the computation requesting party is configured to transmit a two-party data comparison request to the first participant node and the second participant node;
• the first participant node is configured to:
• perform scale transformation on the first private data to obtain a first multi-dimensional vector;
• perform linear scaling on the first multi-dimensional vector to obtain a first encrypted vector;
• and determine a first real number based on the first encrypted vector according to a secure two-party dot product protocol and share the first real number with the second participant node;
• the second participant node is configured to:
• perform scale transformation on the second private data to obtain a second multi-dimensional vector;
• perform linear scaling on the second multi-dimensional vector to obtain a second encrypted vector;
• and determine a second real number based on the second encrypted vector according to the secure two-party dot product protocol and share the second real number with the first participant node, wherein a sum of the first real number and the second real number is equal to a dot product of the first encrypted vector and the second encrypted vector;
• the first participant node is further configured to determine a first comparison sign based on the first real number and transmit the first comparison sign to the computation requesting party;
• the second participant node is further configured to determine a second comparison sign based on the second real number and transmit the second comparison sign to the computation requesting party;
• and
• the computation requesting party is further configured to determine a comparison result of the first private data and the second private data based on the first comparison sign and the second comparison sign.