Normally, Documenting Bitcoin does not post about other cryptocurrencies, but this week became too significant to ignore. In two separate moments, the design choices of the Bitcoin blockchain were proven correct. The first involved Zcash, the most valuable privacy-focused cryptocurrency. Zcash was created to make transactions private by using shielded addresses and zero-knowledge proofs, known as zk-SNARKs. These proofs allow the network to verify that a transaction is valid without publicly revealing the sender, receiver, or amount. Bitcoin made the opposite tradeoff. Its blockchain is transparent by design. Every transaction is public, every coin can be traced through the ledger, and the total supply can be independently audited by anyone running the software. This distinction became clear after Claude AI was used to hack Zcash and identify a critical vulnerability in its shielded system. The flaw allowed unlimited counterfeit coins to be created without normal public detection. The privacy system that hid transaction details also made the monetary supply harder to verify in the simple, public way Bitcoin allows. The second involved Ethereum, the second most valuable cryptocurrency in the world for more than nine years. Ethereum is not only a currency network. It is a smart-contract platform designed for tokens, applications, stablecoins, decentralized finance, and many other assets built on top of it. Today, Tether flipped Ethereum in market value. That moment exposed a different design contrast. Ethereum was built as a broad platform where value is spread across many competing tokens and applications. Bitcoin was built to focus the entire network around one native asset: bitcoin. Bitcoin’s design has often been criticized as too simple, too transparent, and too narrow. This week showed why those choices mattered.(Documenting ₿itcoin 📄)