user119104: Schnorr signatures are often compared as superior to the Elliptic Curve ones. Then why developers added Schnorr  into libsecp256k1 library which is, as the name suggests, an Elliptic Curve library?
Why not create a separate C library? Or is Schnorr signature part of Elliptic Curve signature group?
Thanks

user208: Yes, the BIP340 signature scheme that was added to libsecp256k1 is an Elliptic Curve based variant of Schnorr signatures. Traditionally Schnorr signatures use a group of integer multiplication modulo a large prime, but that's not what is used here. It's integrated into libsecp256k1, because it is a Schnorr scheme over the secp256k1 group, so lots of code is shared between ECDSA and Schnorr.

119104: <p><a href="https://en.wikipedia.org/wiki/Schnorr_signature" rel="nofollow noreferrer">Schnorr signatures</a> are often compared as superior to the Elliptic Curve ones. Then why developers <a href="https://github.com/bitcoin-core/secp256k1/commit/4e43520026f5bcd182d21f0759bac159ef47bb62" rel="nofollow noreferrer">added</a> Schnorr  into <code>libsecp256k1</code> library which is, as the name suggests, an <em>Elliptic Curve</em> library?</p>
<p>Why not create a separate C library? Or is Schnorr signature part of Elliptic Curve signature group?</p>
<p>Thanks</p>
 208: <p>Yes, the BIP340 signature scheme that was added to libsecp256k1 is an Elliptic Curve based variant of Schnorr signatures. Traditionally Schnorr signatures use a group of integer multiplication modulo a large prime, but that's not what is used here. It's integrated into libsecp256k1, because it is a Schnorr scheme over the secp256k1 group, so lots of code is shared between ECDSA and Schnorr.</p>
