SPRUJB6B November 2024 – May 2025 AM2612
This command tests if, for a given x-coordinate, there is a y such that (x,y) is on the elliptic curve. It does not compute y. It raises an error if no such y exists, and otherwise completes successfully.
This command will raise an error if:
| Slot | Name | Description | In ROM? |
|---|---|---|---|
| 10 | b | b-coefficient of the elliptic curve | Yes |
| 11 | px | x-coordinate of the point | No |
| 14 | P | Order of the finite field underlying the elliptic curve if it is not a supported special modulus. | Yes |
| 15 | a | a-coefficient of the elliptic curve | Yes |
On success or on error, this command clears slots 5-9.