#SPARTA is protected against the 51% attack by its technical features and the Proof-of-Stake (#PoS) algorithm. Let's try to get things straight.
What is the 51% attack and why is it dangerous?
The 51% attack is only possible if a miner or a group of conspiring miners controls 51% or more of the network's computing power (#hashrate).
In this situation, malicious miners may run a con in order to make profit. They could control the network at their discretion: adding fraudulent blocks to the blockchain, confirm bogus transactions and reject honest ones, make the same transfer multiple times by reclaiming coins immediately after the transaction.
Can this happen? Has it actually happened before?
Yes, the 51% attack is not just a theory — it's a reality of the cryptocurrency world. With cryptocurrencies that use the Proof-of-Work (PoW) algorithm, the chance of generating a new block and receiving a reward in the form of new coins depends on the miners' hashrate — the higher it is, the more chances they have. This is why many miners unite to make up the so-called mining pools — they pool their hashrates together and increase the odds of generating new blocks.
This is the factor that makes the 51% attack real. Here are some real examples:
In July 2014, the mining pool Ghash.io took possession of 55% of Bitcoin's hashrate and was able to run the attack. However, miners demonstrated honesty and loyalty to #Bitcoin — they voluntarily reduced their respective hashrates and undertook to control these values and limit them to 40% at the most.
In August 2016, blockchains of Ethereum-based cryptocurrencies Krypton and Shift suffered the 51% attack. Fraudsters ran a double spending transaction with these cryptocurrencies on the Bittrex exchange and stole about 22,000 coins from both networks.
The truth is there have been a lot more practical examples.
SPARTA is protected against the 51% attack by PoS and equal chances for nodes that own 1 mln coins
In SPARTA, network support is not dependent on the miners' hashrates — you can easily use a regular computer. This is why users cannot pool their hashrates to increase the odds of generating a block. The block-generating user is determined using a special formula, and chances of generating a block depend on the amount of coins on the user's account.
What is a user has a thousand times more coins than anyone else? Will this user generate blocks all the time which will enable them to run the 51% attack? It's a reasonable question that is relevant for other coins that also use the Proof-of-Stake technology. However, in SPARTA any network user with a balance of at least 1,000,000 SPA has equal chances of generating a new block and receiving new coins as a reward. In other words, chances of generating a block are equal for a node with 1 mln coins and for a node with 20 mln or even 2 bln coins — it makes no difference.
Under such conditions, a possibility of a 51% attack is ruled out by default since pooling of miners' balances does not increase the odds of receiving a reward, so it just doesn't make any sense to create pools.
SPARTA is an easy-to-use, fast and safe cryptocurrency with real decentralization. Join the SPARTA network to see its advantages for yourselves!