How does Polkadot maintain the security of itself and its parachains?

This article is from the [Understanding Polkadot - Basic Knowledge - Network Security] section of Polkadot Wiki.

Shared security, sometimes we call it pooled security in the document, if a chain is considering becoming a parachain of the Polkadot network, then shared security is one of the very important prerequisites. Moving up a level, shared security means that all parachains connected to the Polkadot relay chain by renting parachain slots will benefit from the economic security provided by the relay chain validators.

The concept of shared security differs from interchain protocols based on bridge architectures. For the bridge protocol, each chain is considered a sovereign chain and must maintain its own validator node pool and security. One concern in these protocols is scalability of security. For example, one of the proposals to expand the scale of the blockchain is to expand through altcoins. The emergence of a large number of altcoins can support a huge transaction volume, but at the same time, the transaction volume will be transferred (decreased) to altcoins with lower market capitalization. . A major flaw with this idea is that tokens with lower market caps have less economic security and are more vulnerable to attacks. A real 51% attack case happened recently (Ethereum Classic attack on January 10), where an anonymous attacker used double spending to cause a loss of 219,500 ETC (approximately $1.1 million).

The Polkadot ecological concept sector has an average increase of 4.83% today: Jinse Finance and Economics quotes show that the Polkadot ecological concept sector has an average increase of 4.83% today. Among the 26 currencies, 17 rose and 9 fell, among which the leading currencies were: XOR (+72.67%), OM (+19.03%), and EDG (+13.36%). The leading currencies are: ANKR (-6.08%), CELR (-5.55%), MXC (-3.35%). [2021/4/10 20:06:01]

Polkadot overcomes security scalability concerns because it attracts all economic incentives to the relay chain and allows parachains to have stronger security guarantees from the start. Sovereign chains have to go the extra mile to increase the value of their own tokens, making them less vulnerable to well-funded attackers.

Plasm founder: Plan to build a scalable DEX and make it an IDO platform on Polkadot: Plasm founder Sota Watanabe tweeted that we plan to build a scalable DEX on the Plasm Network, and then make it a Polkadot (Polkadot) platform. ) on the IDO platform. We are happy to work with some projects. [2021/3/19 19:00:04]

Let’s compare the standard security model of current proof-of-work (PoW) chains with Polkadot’s shared security model. Chains protected by their own security models, such as Bitcoin, Zcash, Ethereum, and their derivatives, must create their own network of independent miners and maintain a sufficient proportion of honest hashing power. Since the mining industry is becoming a large industry concentrated towards oligopolies, it is more likely that a single actor will attack a chain. This means that a chain with a smaller hash power could be attacked by a large mining cartel that, on a whim, shifts its hash power from Bitcoin to this new, less secure chain. A low chain can complete the attack. 51% attacks are a reality today and have happened to Ethereum Classic (see previous paragraph), Verge, Bitcoin Gold, and other cryptocurrencies.

The Polkadot ecological project StaFi will release rDOT and rKSM on the mainnet in March: The Polkadot ecological project StaFi tweeted that it has launched rFIS and rETH StakingDrop airdrops in February this year to help increase the adoption of rToken Staking derivatives. The focus in March will be to release rDOT and rKSM on the mainnet and prepare a liquidity mining plan for rToken. rATOM will be launched in mid-April. [2021/3/1 18:04:34]

In Polkadot, there is no difference between chain security. When a parachain is connected to the Polkadot network, the relay chain validator node pool will become the protector of the parachain state transition. The cost of a parachain is simply to run a few collator nodes to keep validators up-to-date on state transitions and attestations/witnesses. Validators will then check whether they are assigned a parachain. In this way, the new parachain can immediately benefit from the overall security of the Polkadot network (Polkadot) as soon as it goes live.

88% of the newly mapped DOT (Polkadot) flows into Huobi: According to CoinMarketCap data, in the past 24 hours, the total transaction volume of DOT (Polkadot Polkadot) was 39.33 million USDT, of which the transaction volume of DOT on Huobi Global Station reached 16.52 million USDT , accounting for 42% of the transaction volume of the entire network, is the exchange with the largest transaction volume of DOT.

According to Polkadot’s official website, as of 9:00 on July 18, the total number of unmapped tokens on the entire network was 1.39 million; as of 9:00 on July 19, a total of 60,000 new mappings were added, of which 53,000 flowed into Huobi, accounting for 88%.

Market analysts believe that at present, Huobi has become a major exchange that newly reflects DOT inflows and the main market for DOT transactions. The advantages of Huobi in terms of overall trading volume, liquidity, and security are the main reasons why it has become the preferred exchange for DOT mapping and trading. [2020/7/19]

Security is independent of the number of parachains connected to the Polkadot relay chain. There is a correlation between security and the number of validators, as more validators will make the network more decentralized and make it harder to crash. The biggest indicator of network security is the economic signal of the number of DOTs bonded and staked. The more DOTs staked by honest validators and nominators, the higher the minimum amount of DOTs an attacker needs to get a validator slot.

Since all state transitions will be secured by Polkadot relay chain validators, most parachains will not have to worry about their own security. However, in some cases (some more experimental ones), a parachain may require its own security. Typically, these situations will revolve around the lack of data available to relay chain validators. An example is that if the state transition function has some succinctness or zero-knowledge proof, then since the relay chain will not be able to provide the data, the parachain will be responsible for keeping its data available. Additionally, for chains with consensus (such as those enabling fast payments on the Blink Network), Byzantine agreement among stakers may be required before parachain blocks can be verified. This protocol is necessary because relay chain validators are not aware of the data associated with fast consensus.

*This article was last updated on 6/1/2020 by joe petrowski*

Original: https://wiki.polkadot.network/docs/en/learn-security

Translation: PolkaWorld

Tags：

ETH