It’s just that as the technology evolves, people have lifted up their expectations and wish Bitcoin to do this and achieve that. Sidechains are among those efforts. In fact, much effort from the community and beyond has been made to make adjustments and improvements on and around Bitcoin
. Well, give some credits to the great Satoshi Nakamoto, Bitcoin came pretty handy already when it was given "birth". The percentage comparison might leave an impression that the sky is unlimited for Ethereum while the possibility with Bitcoin world is limited. But it is just not that simple.
You can do this on the client-side, but doing it inside the smart contract means you only need to send one signature parameter rather than three. Signatures produced by web3.js are the concatenation of r , s and v , so the first step is to split these parameters apart. Splitting apart a byte array into its constituent parts is a mess, so we use inline assembly to do the job in the splitSignature function (the third function in the full contract at the end of this section).
PoX’s Nakamoto consensus differs from PoW’s Nakamoto consensus in that it is resilient under two additional PoX-specific forms degraded mining: discount mining, and external miner monopolization. In these mining modes, the chain’s safety and liveness are preserved, but we classify them as "degraded" because they are still detrimental to the chain’s overall health. PoX’s Nakamoto consensus shares the rest of PoW’s Nakamoto consensus degraded forms of mining, such as selfish mining, block-withholding, and cryptocurrency 51% attacks, but the degree to which these degraded forms can be damaging is mitigated in PoX by the fact that all miner activity is public.
RSK Labs has stated that this is a temporary security measure and that they will relinquish this power once merge-mining engagement goes over 51% of Bitcoin hashrate. At the time of writing, RSK Labs still holds a private key that can be used to limit the amount of bitcoins locked in the peg. The source code indicates that RSK Labs can lift this limitation by sending a special message to the smart-contract that controls the peg.
A detailed description of the mining process and chain-building process can be found in SIP-001 and SIP-007. Each miner is incentivized to build its block on top of the canonical Stacks fork, since this fork is where the rest of the miners (and thus users and exchanges) have spent the most time competing to build on. The canonical fork is always the longest fork by number of consecutive blocks appended.
This is because the act of producing a hidden Stacks fork, where the fork’s block hashes are not known to the honest miners, is the act of producing a hidden canonical Bitcoin fork. This allows the system to leverage Bitcoin’s security budget in order to ensure that all forks are public. Second, the history of block production in all Stacks forks is embedded within Bitcoin. A PoX chain leverages this property not to prevent reorgs, but to make reorgs unprofitable . Therefore, the act of producing a hidden Stacks fork is at least as hard as reorging the Bitcoin chain .
This is in part explained by the fact that simple RSK transactions are 5 times smaller than Liquid counterparts. RSK is currently 10 times cheaper than Liquid (0.0066 USD vs 0.10 USD per simple payment). However, cheap transactions can be a double-edged sword, as they may increase the blockchain’s size beyond acceptable limits for regular users and centralize the peer-to-peer network.
As another example, a PoX chain can recover from long-lived network partitions or even systemic block loss — the longest fork will become the canonical fork, and lost blocks will be "forked around" to produce a new canonical chain from the transactions that were orphaned. In fact, thanks to Nakamoto consensus, the Stacks chain has already automatically recovered by forking around bug-induced network partitions and block loss early in its operation. If Stacks were a PoS chain, it would have crashed instead due to a quorum failure. For example, a PoX chain can recover from a safety failure (a 51% attack) as long as the malicious miners do not outspend the honest miners in perpetuity. The choice to implement Nakamoto consensus in Stacks was made to grant the chain a high degree of resiliency in the face of unfavorable network conditions.
RSK is planning to deploy an account abstraction improvement, which will enable any contract to receive messages directly from an external transaction without source address, achieving complete sender anonymity, if the sender is using Tor. Currently, these user-level solutions hide transacted amounts and destination addresses, but source addresses still can be linked. Protecting source addresses requires either a market of meta-transactions (paying third parties to broadcast your transactions) or modifications to the RSK consensus.
Exchanges, where you exchange your government-backed currency for cryptocurrency
, all require some kind of proof of identity, be it a passport, a driver’s license, or a government-issued ID. There’s another issue, though: Spending is one thing, but buying Bitcoin isn’t anonymous, either. Just like regular banks, to operate, crypto exchanges need to implement know-your-customer (KYC) protocols.