Zcash is a decentralized and open-source cryptocurrency that offers privacy and selective transparency of transactions. Zcash payments are published on a public blockchain, but the sender, recipient, and amount of a transaction remain private. Zcash is based on peer-reviewed cryptographic research, and built by a security-specialized engineering team on an open source platform based on Bitcoin Core's battle-tested codebase. Our improvement over Bitcoin is the addition of privacy. Zcash uses advanced cryptographic techniques, namely zero-knowledge proofs, to guarantee the validity of transactions without revealing additional information about them. How Zcash works Zcash encrypts the contents of shielded transactions. Since the payment information is encrypted, the protocol uses a novel cryptographic method to verify their validity. Zcash uses a zero-knowledge proof construction called a zk-SNARK, developed by our team of experienced cryptographers based on recent breakthroughs in cryptography. These constructions allow the network to maintain a secure ledger of balances without disclosing the parties or amounts involved. Instead of publicly demonstrating spend-authority and transaction values, the transaction metadata is encrypted and zk-SNARKs are used to prove that nobody is cheating or stealing. Zcash also enables users to send public payments which work similarly to Bitcoin. With the support for both shielded and transparent addresses, users can choose to send Zcash privately or publicly. Zcash payments sent from a shielded address to a transparent address reveal the received balance, while payments from a transparent address to a shielded address protect the receiving value. Check out CoinBureau for guide on What is ZCash.
NEM is a highly versatile crypto solution which seeks to adhere to a host of mainstream industry requirements. It is written in Java and JavaScript with 100% original source code. NEM has a stated goal of a wide distribution model and has introduced new features in blockchain technology in its proof-of-importance (POI) algorithm. NEM also features an integrated P2P secure and encrypted messaging system, multisignature accounts and an Eigentrust++ reputation system. Essentially, NEM is designed as a financial blockchain solution and can be used for payment, clearing and settlement in a private environment which is highly controlled. This means that NEM meets several of the regulatory requirements and guidelines in the financial industry. This allows it to be used to settle (change of ownership) any asset via the blockchain. Mijin which is a private chain of NEM has gained popularity and companies such as Hitachi have already embraced it. Why NEM? Many banks around the world have come to accept the importance of blockchain technology. In fact, a good number of banks in the U.S, India and Japan have already started using the technology. Because banks generally employ the smart contract concept, NEM’s platform which is asset-friendly can be used to settle any asset. In settling assets, speed, security, and reliability are very important to a mainstream institution which is what this crypto offers. NEM addresses these issues by repackaging its blockchain into a private chain and presenting it as Mijin. NEM crypto is also applicable in the technology world. Unlike Bitcoin and Dogecoin which use mining to increase the number of coins, XEM uses something called ‘harvesting’. In this process, blocks are generated and a person is rewarded for work contributed using transaction fees. Every block has a certain number of transactions which attract an unknown amount of fees. This keeps the participants incentivized to continue harvesting. For a blockchain user to be allowed to harvest, one must go through a forging mechanism process called Proof-of-Importance (POI). POI is the algorithm used in NEM to time stamp transactions. A NEM user's importance is determined by how many coins they have and the number of transactions made to and from their wallet. POI uses the NCDawareRank network centrality measure, the topology of the transaction graph, as well as a number of other relevant signals to achieve consensus. POI is different from other initiatives which use a fee-sharing model that does not take into consideration one's overall support of the network. In proof-of-stake systems a person needs to have large numbers of coins to form a block, but in NEM transactions volume and trust become factors. This was designed to encourage users of NEM to not simply hold XEM but instead actively carry out transactions. To be eligible for entering the importance calculation, an account must have at least 10,000 vested XEM. All accounts owning more than 10,000 vested XEM have a non-zero importance score. With a supply of 8,999,999,999 XEM, the theoretical maximum number of accounts with non-zero importance is 899,999. In practice, the number of actual accounts with non-zero importance is not expected to approach the theoretical max due to inequalities in held XEM and also the temporal costs associated with vesting. If NEM becomes very popular, a threshold of 10,000 vested XEM could be undesirable. If necessary, this number could be updated in the future via a hard fork, which is the same procedure for adjusting transaction fees and other parameters related to harvesting.