Tom-521 curve from https://eprint.iacr.org/2021/1183.pdf

Parameters

SAGE

p = 0x200000000000000000000000000000000000000000000000000000000000000002c54be78524c33584f734a266748b2063accf5028e6778dc5056476d0690853249
K = GF(p)
a = K(0xef6432c21701cc48c63fb9263e14ba76d4a94ba14d173b134e3032b0e2e543180eb6725125992a7d00162a5f57d21918b0766364eeb53c53bb12f405dac1d527e2)
b = K(0x3cbc65d1e0245d79703b18e9aaea1ac6d67f87a2cd4bd84b9e6df6a45a979c481825ca5a857270fc890352f9fac7fd6020deaabb28d099718f0f77a4eec222871d)
E = EllipticCurve(K, (a, b))
# No generator defined
E.set_order(0x01ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff * 0x01)

PARI/GP

p = 0x200000000000000000000000000000000000000000000000000000000000000002c54be78524c33584f734a266748b2063accf5028e6778dc5056476d0690853249
a = Mod(0xef6432c21701cc48c63fb9263e14ba76d4a94ba14d173b134e3032b0e2e543180eb6725125992a7d00162a5f57d21918b0766364eeb53c53bb12f405dac1d527e2, p)
b = Mod(0x3cbc65d1e0245d79703b18e9aaea1ac6d67f87a2cd4bd84b9e6df6a45a979c481825ca5a857270fc890352f9fac7fd6020deaabb28d099718f0f77a4eec222871d, p)
E = ellinit([a, b])
E[16][1] = 0x01ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff * 0x01
\\ No generator defined

JSON

{
  "name": "Tom-521",
  "desc": "Tom-521 curve from https://eprint.iacr.org/2021/1183.pdf",
  "form": "Weierstrass",
  "field": {
    "type": "Prime",
    "p": "0x200000000000000000000000000000000000000000000000000000000000000002c54be78524c33584f734a266748b2063accf5028e6778dc5056476d0690853249",
    "bits": 521
  },
  "params": {
    "a": {
      "raw": "0xef6432c21701cc48c63fb9263e14ba76d4a94ba14d173b134e3032b0e2e543180eb6725125992a7d00162a5f57d21918b0766364eeb53c53bb12f405dac1d527e2"
    },
    "b": {
      "raw": "0x3cbc65d1e0245d79703b18e9aaea1ac6d67f87a2cd4bd84b9e6df6a45a979c481825ca5a857270fc890352f9fac7fd6020deaabb28d099718f0f77a4eec222871d"
    }
  },
  "order": "0x01ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
  "cofactor": "0x01"
}