# StarkNet Presentation
### What is StarkNet
StarkNet as a permissionless decentralized ZK-Rollup operating as an L2 network over Ethereum
It provides scalability without compromise on composability and security

Ethereum and Bitcoins don't have the same perfomance as credit cards and banks.
Reason is Accountability.
Banks and Credit Cards have delegated accountability - Central authority

Blockchains use inclusive accountability - Expect everyone to process every transaction not a single party, Don't Trust, Verify. Sacrifice Privacy(everyone sees because they validate what you are doing.) and Scalability.
Blockchains are replicated ledgers, workload is replicated everywhere.

Credit card transactions are executed and verified by a single or few parties, unlike blockchains everything has to be replicated accross all parties.

### Why it is the best L2 Solution
Scaling Inclusive Accountability Options
1. Increase Blocksize/block limit - Trust Big Computer to do more transactions. Require parties to have more computing power.
2. Fraud Proof Rollups (Arbitrium, Optimism) - Semi Inclusive, Trust A few Big Computers. Big computers do computation while giving everyone the ability to audit the transaction by submitting a fraud proof. It works but requires trust by assuming someone is watching the network. In a way relying on network validators.
3. ZK-Rollup, it relies on cryptographic primitive which is proof of computation, like hashes, digital fingerprint. Mathematical proof allows you to prove that a certain amount of computation was done correctly without you doing the computation.
A way for Alice to Prove to Bob that she did a big amount of computation correctly that lead to a specific results, and she can send to Bob, the program, the results and proof of execution that gives Bob cryptographic guarantee that the job was done correctly and ended at these results and proof shows that it cannot be disputed.
4. More of Proof Of Work, when someone submits a hash, you are confident that amount of computation was done without running the computation yourself.
5. ZK-Rollups vs Optimistic Rollups - THe data on the later is posted on Ethereum, available on Ethereum but not interpreted by Ethereum, not executed by Ethereum. Security of the system is reliant upon someone executing these transactions offchain and verify their validity and if one transaction is not valid they a proof can be submitted to Ethereum to check it. Expect someone will check it and if there is fraud, someone will prove it.
6. Zk-Rollups, everything including validation is done by Ethereum before state change.
7. Theoretically, a prover with enough computational power could create fake proofs, and this is one of the reasons quantum computers are considered by many as a threat to zk-SNARKs
8. Zero Knowledge Proofs, allow one individual to prove to another that a statement is true, without disclosing the information beyond the validity of the statement.

### STARK Cryptography -> Who are the prover, verifier, what is witness and proof

1. On StarkNet, there is a prover, who will gather transaction and prove correct execution of these transactions gather them in proof and send them to Ethereum. Because they are mathematical proofs, they can be interpreted by players outside the blockchain, and Ethereum itself is able to validate this proof. (Prove the work)
2. In Blockchain every transaction is sent to nodes to validate and update account states, prover is able to process transactions and generate proof which will effectively change state in accounts.
3. Verifier, Party checking the proof happened, some amount of computation/work was done. Basically full nodes on Ethereum validating the chain.
4. Proofs reveal no information about exact transactions. The only thing you know is what you can learn from the computational statement. Proofs reveals no information and shields private inputs that went into the proving process.
5. Zero-knowledge proofs allow one individual to prove to another that a statement is true, without disclosing any information beyond the validity of the statement. The parties involved are commonly referred to as a prover and a verifier, and the statement they hold in secret is called a witness

Solving the inclusive accountability
1. Everything is sent to the prover who does all the computation and have everyone verifying it without doing the computation and guaranteeing the results.
2. Verifying a proof is less expensive than doing the computation entirely.

ZK- STARKS are built on top of non collision in SHA -256, which are quantuam resistant.