Someone said that the parity of the target private key does not matter 
This has implications for the choice of divisor.
If the private key is divisible by 2 without a remainder, then the divisor is correct. PrivKey % 2 = 0.
But because the target key is not known, the correct divisor can only be random.
The same applies to public keys, which also have parity.
Example of correct divisors for a test private key:
It is impossible to find the correct divisor for a public key; you need a private key.
This has implications for the choice of divisor.
If the private key is divisible by 2 without a remainder, then the divisor is correct. PrivKey % 2 = 0.
But because the target key is not known, the correct divisor can only be random.
The same applies to public keys, which also have parity.
Example of correct divisors for a test private key:
Code:
[i] NB: 0 DIVKey: 1 Inverse DivideKey: 1
[i] 1 TRUE DIVIDER NB: 4 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] 2 TRUE DIVIDER NB: 62 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x7 Result: 0x3A439FEDFED17728EE15703CB5D194DC
[i] 3 TRUE DIVIDER NB: 126 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x1 Result: 0x197D95F81F7BA421E829611A8F8BB1204
[i] NB: 200 DIVKey: 10C Inverse DivideKey: 2DD9CA81E9131ABF0B7672A07A44C6AF8899965ECF27C0FF3D1A3724AED80BB
[i] 4 TRUE DIVIDER NB: 329 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] NB: 400 DIVKey: 23C Inverse DivideKey: 51E6EFE35B4CFAA11E6EFE35B4CFAA117EDBBF8316F5AB35212C7A71F936F3C2
[i] 5 TRUE DIVIDER NB: 418 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x15B Result: 0x12CE43D9BA45157E164076DAC9CF14C
[i] 6 TRUE DIVIDER NB: 585 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x4 Result: 0x65F657E07DEE9087A0A5846A3E2EC481
[i] NB: 600 DIVKey: 23E Inverse DivideKey: 4039164CB5F71484039164CB5F71483FE77978885DECC19E99607B9F4FE2CBB
[i] NB: 800 DIVKey: 1C0 Inverse DivideKey: 6D24924924924924924924924924924899E043E4A2BAF6997935B04F767BB3D2
[i] 7 TRUE DIVIDER NB: 809 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x373 Result: 0x763E70ED25521F5892DEADDA978CEC
[i] 8 TRUE DIVIDER NB: 834 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x1 Result: 0x197D95F81F7BA421E829611A8F8BB1204
[i] NB: 1000 DIVKey: DE Inverse DivideKey: B9A85C40939A85C40939A85C40939A84D81BA4D0CFD743C5DAAE799D7904C09F
[i] 9 TRUE DIVIDER NB: 1062 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x15B Result: 0x12CE43D9BA45157E164076DAC9CF14C
[i] 10 TRUE DIVIDER NB: 1072 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] 11 TRUE DIVIDER NB: 1127 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x15B Result: 0x12CE43D9BA45157E164076DAC9CF14C
[i] 12 TRUE DIVIDER NB: 1169 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] NB: 1200 DIVKey: 14C Inverse DivideKey: 80C565C87B5F9D4D1BC2503159721ED743AFDC9C2231A3E05E2CE713F071A6FE
[i] 13 TRUE DIVIDER NB: 1337 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x1C Result: 0xE90E7FB7FB45DCA3B855C0F2D746537
[i] NB: 1400 DIVKey: 2C0 Inverse DivideKey: A28BA2E8BA2E8BA2E8BA2E8BA2E8BA2DBD141E710462D73192E306F16890FE86
[i] 14 TRUE DIVIDER NB: 1477 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] 15 TRUE DIVIDER NB: 1542 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x4 Result: 0x65F657E07DEE9087A0A5846A3E2EC481
[i] 16 TRUE DIVIDER NB: 1578 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x373 Result: 0x763E70ED25521F5892DEADDA978CEC
[i] NB: 1600 DIVKey: 1EE Inverse DivideKey: 79C8084A9F9C8084A9F9C8084A9F9C7FE9E86E4447FBAEAF98EB545CE5A3A7DA
[i] 17 TRUE DIVIDER NB: 1619 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2B6 Result: 0x96721ECDD228ABF0B203B6D64E78A6
[i] NB: 1800 DIVKey: 346 Inverse DivideKey: 50F46433527B6AEBD67415FEC72DD2C938973869F12AD2BF30BEDBE9EEBFE597
[i] 18 TRUE DIVIDER NB: 1880 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x1C Result: 0xE90E7FB7FB45DCA3B855C0F2D746537
[i] NB: 2000 DIVKey: 4A Inverse DivideKey: 2CF914C1BACF914C1BACF914C1BACF9112F534A510F48ADA1066AFBECAA1BF5B
[i] Data Saved in file DivideKeys.txt
[i] 1 TRUE DIVIDER NB: 4 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] 2 TRUE DIVIDER NB: 62 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x7 Result: 0x3A439FEDFED17728EE15703CB5D194DC
[i] 3 TRUE DIVIDER NB: 126 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x1 Result: 0x197D95F81F7BA421E829611A8F8BB1204
[i] NB: 200 DIVKey: 10C Inverse DivideKey: 2DD9CA81E9131ABF0B7672A07A44C6AF8899965ECF27C0FF3D1A3724AED80BB
[i] 4 TRUE DIVIDER NB: 329 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] NB: 400 DIVKey: 23C Inverse DivideKey: 51E6EFE35B4CFAA11E6EFE35B4CFAA117EDBBF8316F5AB35212C7A71F936F3C2
[i] 5 TRUE DIVIDER NB: 418 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x15B Result: 0x12CE43D9BA45157E164076DAC9CF14C
[i] 6 TRUE DIVIDER NB: 585 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x4 Result: 0x65F657E07DEE9087A0A5846A3E2EC481
[i] NB: 600 DIVKey: 23E Inverse DivideKey: 4039164CB5F71484039164CB5F71483FE77978885DECC19E99607B9F4FE2CBB
[i] NB: 800 DIVKey: 1C0 Inverse DivideKey: 6D24924924924924924924924924924899E043E4A2BAF6997935B04F767BB3D2
[i] 7 TRUE DIVIDER NB: 809 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x373 Result: 0x763E70ED25521F5892DEADDA978CEC
[i] 8 TRUE DIVIDER NB: 834 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x1 Result: 0x197D95F81F7BA421E829611A8F8BB1204
[i] NB: 1000 DIVKey: DE Inverse DivideKey: B9A85C40939A85C40939A85C40939A84D81BA4D0CFD743C5DAAE799D7904C09F
[i] 9 TRUE DIVIDER NB: 1062 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x15B Result: 0x12CE43D9BA45157E164076DAC9CF14C
[i] 10 TRUE DIVIDER NB: 1072 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] 11 TRUE DIVIDER NB: 1127 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x15B Result: 0x12CE43D9BA45157E164076DAC9CF14C
[i] 12 TRUE DIVIDER NB: 1169 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] NB: 1200 DIVKey: 14C Inverse DivideKey: 80C565C87B5F9D4D1BC2503159721ED743AFDC9C2231A3E05E2CE713F071A6FE
[i] 13 TRUE DIVIDER NB: 1337 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x1C Result: 0xE90E7FB7FB45DCA3B855C0F2D746537
[i] NB: 1400 DIVKey: 2C0 Inverse DivideKey: A28BA2E8BA2E8BA2E8BA2E8BA2E8BA2DBD141E710462D73192E306F16890FE86
[i] 14 TRUE DIVIDER NB: 1477 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2 Result: 0xCBECAFC0FBDD210F414B08D47C5D8902
[i] 15 TRUE DIVIDER NB: 1542 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x4 Result: 0x65F657E07DEE9087A0A5846A3E2EC481
[i] 16 TRUE DIVIDER NB: 1578 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x373 Result: 0x763E70ED25521F5892DEADDA978CEC
[i] NB: 1600 DIVKey: 1EE Inverse DivideKey: 79C8084A9F9C8084A9F9C8084A9F9C7FE9E86E4447FBAEAF98EB545CE5A3A7DA
[i] 17 TRUE DIVIDER NB: 1619 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x2B6 Result: 0x96721ECDD228ABF0B203B6D64E78A6
[i] NB: 1800 DIVKey: 346 Inverse DivideKey: 50F46433527B6AEBD67415FEC72DD2C938973869F12AD2BF30BEDBE9EEBFE597
[i] 18 TRUE DIVIDER NB: 1880 TestKey: 0x197D95F81F7BA421E829611A8F8BB1204 Divider: 0x1C Result: 0xE90E7FB7FB45DCA3B855C0F2D746537
[i] NB: 2000 DIVKey: 4A Inverse DivideKey: 2CF914C1BACF914C1BACF914C1BACF9112F534A510F48ADA1066AFBECAA1BF5B
[i] Data Saved in file DivideKeys.txt
It is impossible to find the correct divisor for a public key; you need a private key.