Function: hashToG2()

The function maps a uint256 value to a point in the group ${\mathbb{G}}_2$. To fulfill BLS security, this function should be collision-resistant and not reveal the discrete logarithm of the resulting point.

Inputs

• h

  • Validation: No validation.

  • Impact: Map a value to ${\mathbb{G}}_2$.

Branches and code coverage (including function calls)

Intended branches

Function call analysis

• mapToG2(h)

  • External/Internal? Internal.

  • Argument control: The arguments are controllable by the caller, but the value is usually a hash.

  • Impact: Maps a value to a point on the curve.

• ECTwistMulByCofactor(map.X[1], map.X[0], map.Y[1], map.Y[0])

  • External/Internal? Internal.

  • Argument control: No.

  • Impact: Clear the cofactor to have a point in ${\mathbb{G}}_2$.