Perhaps the most powerful cryptographic technology to come out of the last decade is
general-purpose succinct zero knowledge proofs, usually called zk-SNARKs(Zero Knowledge
Succinct Non Interactive Arguments of Knowledge).
Fromday oneit has always been evident that, that the problem of scaling could significantly
limit the potential of blockchain, security and decentralization remain paramount and so
scalability suffers. For clarity’s sake I’ll describe scalability here as The chain’s ability to
perform more transactions at reduced gas costs( increased throughput, reduced latency).In
a centralized system, there is a third-party that charges transaction fees to execute
transactions. This third-party monitors and controls all of the stakeholders’ data, who are
participating in the online transaction in a consolidated manner. No such party exists on the
blockchain as it is entirely peer to peer.
In response to what can best be described as the casting down of the proverbial gauntlet,
talented minds in the field of computing with the required foresight and vision to sought to
proffer solutions to this latest, most daunting of challenges.
In the early days of the endeavour numerous technologies were deployed to abate the
problem , and though most worked they had to be trade-offs, what one lacked another
provided and so the cycle went. Shards and sidechains are two of the more notable solutions.
Sharding It focuses on dividing the blockchain network into smaller and easily manageable
parts, known as shards. Sidechains are another solution, and is simply a separate blockchain
linked to the main blockchain (mainchain). It serves as a transactional chain adjacent to the
blockchain, especially in the case of large batch transactions.
NowRollups have come along, at its core a rollup is simply a function computed over an
array of inputs( in this case transaction and state data from the mainchain ). Rollups have
proven to be the mosteffective of all solutions provided so far. Optimistic rollups are a
rollup sub-type,considered “optimistic” because they assume off-chain transactions are valid,
This separates optimistic rollups from zero-knowledge rollups that publish cryptographic
proofs of validity. They reduce computation on the main Ethereum chain by processing
transactions off-chain, significantly improving processing speeds. These rollups rely on a
fraud-proving scheme to detect incorrect transactions. After a rollup batch is submitted on
Ethereum, there’s a time window ( a challenge period) during which anyone can challenge
the results of a rollup transaction by computing a fraud proof. If the rollup batch is
unchallenged after the challenge period elapses, it is deemed valid and accepted on
Ethereum.If the proof succeeds, protocol re-executes the transaction(s).
ZK-Rollups on the other hand, rely on cryptographic proofs generated by so called zero
knowledge algorithms. Aptly named due to the fact that a zk-SNARK allows you to generate
proof that some computation has some particular output, such that the proof can be verified
quickly even if the underlying computation takes a longer time to run, random sampling of
transaction data provides the proof necessary for the system to work. The three primary
components of a zero-knowledge rollup include a smart contract on Ethereum, a prover, and
a set of verifiers. A prover generates cryptographic proofs of transaction validity on the
layer-2 chain, while verifiers are a group of nodes that confirm these proofs and submit
At this point it is important to note that rollups are relatively novel and care should be taken
in developing the system to avoid buggy behaviour, fail-safes and audits should help prevent
exploits, still it is inherently risky to lean on an external program to handle transactions.
Oluijimi is a Blockchain Analyst. Can be reached at: Email- jimijay.oj@gmail.com
Twitter- dafejay
By: JOSHUA OLUJIMI