Can somebody give a brief technical explanation how exactly the tree parameters attached to the transaction are defined and used to authenticate the sender ?
To summarize. Three parameters (t, r, s). Basically, the verifier can take the modular inverse of s and use it, along with the public key of the sender (which can itself be recovered from the signature), to reconstruct r. It all relies on the magical properties of 'addition' in the finite field group defined by the elliptic curve. The ability to reconstruct r is the verification.