Patent ID: 11870892
Assignee: NEC CORPORATION
Field: Control (Instruments)
Classification: CPC H  G | IPC G  H

Claim 8:
9. A secret calculation method comprising:
receiving, by a processor, a first DNA sequence and a second DNA sequence from a control server;
performing, by the processor, a secret calculation as to an edit distance between the first and second DNA sequences, including generation of a dynamic programming (DP) matrix having a plurality of elements based on the first and second DNA sequences, and calculation of a score for each element; and
transmitting, by the processor, a result of the secret calculation back to the control server, the control server then decoding the result,
wherein the calculation of the score for each element includes:
receiving a first share and a and a second share that are secret-shared and that each belong to a residue class ring modulo 2n, where n is a natural number, the first share is ≥0, and the second share is <2n;
determining a natural number t such that an absolute value of a difference value between the first share and the second share is less than or equal to the natural number t and such that t<2n-1;
determining a natural number m that satisfies 2m-1≤t<2m≤2n-1, where the difference value has a number of bits greater than m such that an m-th bit of the difference value is not a most significant bit of the difference value;
incompletely calculating the difference value between the first share and the second share, by performing bit-composition for each of a plurality of bits of the difference value from a least significant bit to the m-th bit, such that not all of a plurality of bits of the difference value are calculated; and
performing the comparison in magnitude based on the difference value that has been incompletely calculated,
wherein incompletely calculating the difference value is sufficient for performing a comparison in magnitude of the first share and the second share, such that the comparison in magnitude is still accurate even though the difference value has been incompletely calculated,
wherein incompletely calculating the difference value, as opposed to completely calculating the difference value for all the plurality of bits, improves processing speed while still providing for the comparison in magnitude being accurate.