# Hash function a ring-signature-based range proof

For a ring-signature-based range proof (e.g. Ring Confidential Transactions , section 5.0.1) it is required to use some hash function from $$\{0,1\}^* \to \text{scalar}$$.

Is it safe to take for this purpose not a PRF (like Blake2s), but Pedersen hash (which is collision resistant but has group structure) and use $$X$$ or $$Y$$ coordinate of the curve point as the desired scalar?