Blockchains, with their primary focus on decentralization, open participation, and resilience, inherently lack efficiency, scalability, and privacy. Similar to parallel computing algorithms, the scalability of a blockchain-based system depends on the extent to which computational tasks can be moved off-chain. Zero knowledge techniques, such as recursive SNARKs, offer an effective means of shifting computation off-chain, requiring only proof verification as part of the consensus process. Mina demonstrates the use of these techniques in its consensus algorithm Ouroboros Samasika and zkApps. Privacy poses a challenge in blockchain systems due to their open public ledgers. However, zero knowledge proofs enable reduced data exposure on the public ledger and allow fine-tuning of the level of disclosure. Etonec's payment system serves as an exemplary application showcasing enhanced privacy in blockchains.