Public SECR
An unmodified Pons ERC-20. No transfer hooks, no blacklist, nothing a token scanner would flag.
Shielding
Shielding transfers SECR into the Quadratic Arithmetic Program and credits shares. Shares are tracked per address in sharesOf; the Quadratic Arithmetic Program never needs to know which addresses are stealth.
Accounting
The Quadratic Arithmetic Program tracks totalBacking and totalShares. Every path that moves tokens updates both and emits VaultUpdated, so anyone can audit them.