General Overview -
Zcash is a cryptocurrency network that launched in October of 2016. It is directly derived from the Bitcoin core software, but has been modified in order to enhance user privacy. Zcash (ZEC) uses a new technology called zero-knowledge proofs. This allows one to prove something without requiring the prover to reveal any sensitive information. It gets its name from the fact that zero knowledge is revealed to the verifier in the process. The anonymous transactions produced from this technology are referred to as shielded transactions in Zcash.
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Zcash uses cutting edge math and science to create a privacy protecting blockchain. Specifically, it uses cryptographic functions that are called zk-SNARKs. With a zk-SNARK, a computer or network of computers can take some otherwise encrypted and unreadable data and prove certain limited facts are true about that data without revealing anything else. So in the case of payments made to and from a shielded Zcash address, using a zk-SNARK built into the protocol software, the network can prove to any user that, all outgoing transactions equal all incoming transactions (i.e. no new money was created), but the zk-SNARK function proves it without revealing the specifics of those individual transactions, all the data that would be used to compromise your privacy.
This differs from Bitcoin where if your address is ever shared publicly, anyone can view your balance and all other bitcoin addresses you have ever transacted with. Even if you don’t share your address publicly, companies like Chain analysis have built software that can de-anonymize your address if you have transacted with other addresses that are not anonymous. Imagine if everyone you knew, and even strangers, could know how much money you had in your bank account, and how you spent your money. Despite perfectly legitimate transactions, you likely do not want this information available to the entire world.
Zcash also provides encrypted memo fields, which allows a secret message to be sent from the sender to receiver. This can be compared to writing a note on a check but instead of anyone handling the check being able to see it, only the holder of the view key is able to.
The Zcash dev team consists of 22 employees, and is led by cryptography guru, Zooko Wilcox. Zcash and Bitcoin both have a total supply of 21 million units and are released through a process called mining. One unique aspect of Zcash is that the corporate development team and the non-profit Zcash Foundation are funded directly from the blockchain. To achieve this, 20% of the mining reward for Zcash for the first 4 years goes to the stakeholders of the Zcash company (founders, employees, advisors, investors) resulting in 10% of the overall total supply. This “Founders’ Reward” provides funding and incentive-alignment for the continued support and improvement of Zcash
Writing on the zcash blog, co-founder Zooko Wilcox and CTO Nathan Wilcox detailed two milestone upgrades – "Overwinter" and "Sapling" – the latter of which was discussed in a roadmap update earlier this year. According to the post, the goal of next year's upgrades is to "further upgrade Zcash's performance, security, and usability." The first update, Overwinter, is scheduled to go live in June 2018. Per the post, that upgrade is focused on "making itself and future network upgrades safer for users, even in the case of governance contention." Though light on detail at present, the Wilcoxes said that future details about the update would be released in a future blog post. The second one, set to take place in September, is centered around its "Sapling" protocol, which is aimed at boosting the capability of the cryptocurrency's privacy-oriented shielded transactions.