pos--Rights proof mechanism

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Ppcoin:peer-to-peer crypto-currency with Proof-of-stake

PPC: A point-to-point interest proof electronic password currency
Sunny King, Scott Nadal
(Sunnyking9999@gmail.com, scott.nadal@gmail.com)

August 19th, 2012

Summary:PPC is a derivative of the BTC from the Nakamoto created by the electronic password currency, to the proof of rights (Proof of Stake, hereinafter referred to as POS) to replace the workload certificate (Proof of work, hereinafter referred to as POW) to maintain network security. In this hybrid design, the POW works primarily in the initial mining phase. In the long run, the safety of PPC networks is not dependent on energy consumption. PPC is therefore an energy-saving and cost-competitive electronic password currency. POS is based on the age of coin and is generated by a hash operation that is similar to BTC by each node, except that its search space is limited. The history of blockchain and transaction settlement are further protected through a centralized broadcast inspection mechanism.

BackgroundSince Satoshi created bitcoin in 2008, the design concept of the work proof (POW) has become the mainstream idea of electronic money. In the design of Nakamoto, the POW is the backbone for securing mining and BTC.

In October 2011, we realised that the age of coin could be a design other than the Nakamoto POW design, the proof of interest (POS). Since then, we have been thinking about using POS to build a secure model of peer-to-cash and a part of the coinage process, and the POW is primarily in the initial coinage phase, and the importance is diminishing. The design attempts to demonstrate that in the future it is still possible to peer into electronic money without relying on energy consumption. We name this project PPC.

coin age (Coin ages)
At least in 2010, Nakamoto in the BTC design and used the concept of currency age to prioritize transactions, but this concept does not play an important role in its security model. The age of currency is simply defined as the holding time period of the currency. A simple example: If Li Ming received 10 coins from Han Mei and held 90 days, then Li Ming collected 900 currency days of the age of currency.

In addition, if Li Ming used the 10 coins received from Han Mei, we thought Li Ming was consumed (destroyed) by the age of coins accumulated from the 10 coins.

To simplify the calculation of currency age, we introduced the concept of timestamps for each transaction. The protocols associated with block timestamps and transaction timestamps are hardened to determine the operation of the age of the currency.

POS Benefits ProofThe POW is a major technological breakthrough in Nakamoto, but the nature of the POW means that the BTC needs to consume energy to maintain its operations, and that maintaining such a network can be costly. This is supported by a combination of inflation and transaction costs. As the BTC network's mining output declines, it may eventually increase transaction costs to maintain the security of the entire network. Naturally, we ask whether a centralized electronic currency must consume a lot of energy (to keep it running). Therefore, PPC is a very important breakthrough in theory and technology, that is, the electronic money system is not necessarily dependent on energy consumption to maintain its security.

As early as in the 2011 BTC Circle, there was a discussion on the concept of POS proof of entitlement. Presumably, POS refers to a proof of currency ownership. The age at which a transaction is consumed can be considered a form of POS. We independently discovered the concept of POS and Currency age in October 2011, when we realized that by carefully re-designing BTC coinage and Safe mode, POS could actually replace most of the POW's functionality. This is mainly because, like the workload Proof POW, the POS benefits prove can not be easily forged. This, of course, is also a key feature of the monetary system-to prevent counterfeiting. From a philosophical point of view, money is a "proof of workload" in the past, so it can replace the proof of workload.

Block generation under POS designIn our hybrid design, chunks are divided into two forms, the POW block and the POS block.

Figure: Structure of POS transactions (interest currency)


In this new type of block POS is a special transaction called interest Currency (Coinstake) (named after a special transaction in BTC: The currency basis (Coinbase). In the interest currency (Coinstake) transaction, the block holder can consume his currency for interest,
At the same time get the priority of generating a chunk for the network and making coins with Pos. The first input of the interest currency is called the core (Kernel) and needs to conform to a hash target protocol. The generation of POS blocks is random, and the process is similar to POW. One important difference, however, is that (POS) random hashing is done in a confined space (specifically 1 hash/of unused wallet output * seconds), rather than being looked up in an unrestricted space like POW, so there is no need for a lot of energy consumption.

The random hash target to be met by the equity core (kernel) is the target value of the age of the currency (coin * Day coin-day) that is consumed in the core (this is different from the BTC POW, and each node of the BTC is the same target value). Therefore, the more coins the core consumes, the easier it will be to meet the target agreement. For example, if Li Ming has 100 ppc in his wallet and has not moved for 1 years, he can expect to generate a core of interest within 2 days (a chunk that is personally understood as POS); Similarly, if Han Mei has 200 PPC and has not been used for 1 years, she may be able to generate an equity core within 1 days.

In our Pos and POW designs, the target values for random hashes are continuously adjusted. This differs from BTC approximately every two weeks. The main purpose is to avoid sudden fluctuations in mining output.

POS-based coinage (minting)In addition to the POW block of BTC, there is a new POS coinage process in PPC. The POS block will generate interest coins based on the age of currency consumed in the currency transaction. The design is set to 1 cents a year (interest) per currency to avoid future inflation.

Although we retained the POW during the coinage to make the initial coinage more convenient, it was expected that in a purely POS system, the initial coinage could be planted in the creation block in the form of an IPO in the real-world stock market.

Main link ProtocolThe standard of judging the main chain has been converted into a judgment on the age of consumption of coins. Each chunk of the transaction will submit its consumed age to the block, to increase the score of the block. The block that gets the highest age of consumption will be selected as the primary chain.

This is different from the protocol for the main chain where POW is the most heavy workload in the BTC Master chain protocol.

This design mitigates some of the concerns about the 51% attack, because in a BTC network, an honest node requires at least 51% of the calculation to maintain the security of the network. (And in the POS block, to do 51% attacks) first to control a large number of PPC, the cost may be higher than the calculation of 51%, which increases the cost of the attack (attackers need to control more than 51% PPC). Second, when attacking the network, the attacker's currency age is also consumed,

This will make it more difficult for attackers to prevent transactions from entering the main chain. (The analogous force increase is not only to increase the molecule, but also to increase the denominator.) ）

Check mechanism: Protect historical dataUsing the total age of the consumed coins to determine the disadvantage of the main chain is that it reduces the cost of attacking the entire blockchain history. Even though BTC has a strong mechanism to protect historical data, Nakamoto in 2010 proposed a calibration mechanism to protect the blockchain history from any changes that might have been made to the blockchain before the checkpoint.

Another worry is that the cost of double payments can also be reduced, as attackers can accumulate a certain amount of currency to force the blockchain to regroup. In order to make the system commercially operational, we have introduced a central calibration mechanism that will probably be broadcast to the whole network several times per day to freeze the blockchain and settle transactions. This new calibration mechanism is similar to the BTC alarm system.

Laurie (2011) proposed that BTC did not fully address everyone's concern that the calibration mechanism was not released to everyone. We tried to design a workable calibration mechanism that was centralized, but found it difficult to fight the network fork (fork). Although the verification mechanism for broadcast to the whole network is a centralized form, we consider this to be acceptable until there is no centralized solution.

Another reason for using a centralized broadcast verification mechanism is that in order to withstand a class of Dos attacks, the equity core must be validated before each node accepts a POS block to the Local database (block tree). Because of the BTC node data pattern (trade index), a deadline is required for data validation to ensure that all nodes have the ability to validate joins to each of the equity cores before the POS block is accepted for block access. From a practical standpoint, we decided not to modify the node's data schema but to use the central calibration mechanism. Our solution is to modify the currency age calculation, set a minimum currency age, say one months, below which the number will be calculated as zero. The central inspection mechanism is then used to ensure that all nodes agree to all transactions that are greater than 1 months old, since the core requirement is no less than 0 of the age of the currency, allowing the core of the allowed benefits to be validated so that the output greater than one months must be used.

block signature and dual equity agreementEach chunk must be signed by its owner to avoid the same POS being copied and used by the attacker.

To protect against attackers using a single pos to generate multiple blocks for Dos attacks, we have designed a dual-equity agreement. Each node collects all interest currency transaction information that it touches (core, timestamp) pairing. If

A received chunk contains the pairing information (core, timestamp) in the other previously received chunks, and we will ignore this chunk until the latter is isolated (orphaned).

Energy SavingWhen the POW mining output approaches zero, its incentive to the miners will become weaker. In the long run, as miners lose interest in using POW-mode mining, the energy consumed by the network drops to very low levels. Unless the volume/transaction costs rise to a fairly high level, the BTC network will struggle to maintain such energy consumption. In our design, even if the PPC network consumes nearly 0 of the energy, it is still protected by the Pos. If an electronic code currency allows the POW to be zero, we call this currency a long-term energy-saving currency.

Other ConsiderationsWe modified the POW's mining yield to vary with the difficulty, rather than adjusting to the block height (time). When mining difficulty rises, the POW mining yield decreases. Compared to the half-step output of BTC, the PPC output curve is relatively smooth to avoid artificially shaking the market. More specifically, mining output will be halved whenever the difficulty increases by 16 times times.

Under Moore's Law, in the long run, the POW's yield does not differ greatly from the expansion behavior of the BTC's Tonghua. According to conventional wisdom, we think it would be wiser for markets to favour low-inflation currencies rather than high-inflation currencies, although some mainstream economists have harshly criticized BTC for idealistic reasons.

Babaioff et al. (2011) After studying the effect of transaction costs, it is believed that the transaction costs will encourage the miners to not cooperate with each other. In our design, this attack is aggravated. So we no longer reward trading fees for miners who find chunks. We decided to destroy the transaction costs. This removes the motive for the miners not to recognize each other's chunks. It also became a deflationary measure to balance the inflation generated by POS coinage.

We also implement transaction fees at the agreement level to prevent block expansion attacks.

In our study, in addition to the POW and POS, we also found a third proving system, POE (Proof of Excellence, the best proof of the trial translation). In such a system, a certain mining competition can be organized regularly to distribute mining revenues based on the performance of the participants, simulating different rewards for real-life competitions. While this system tends to consume energy when AI is dominant in participating competitions, we still find this concept very interesting because it provides some kind of smarter way to consume energy.

ConclusionWhen validating our designs on the market, we wanted POS to be a more competitive electronic cipher currency than POW, as it eliminated the reliance on energy consumption, thus achieving low inflation/low transaction costs at comparable levels of cyber security.

Reference Babaioff M. et al.: On Bitcoin and red balloons.

Laurie B.:D ecentralised Currencies is probably impossible (but let's at least make them efficient). (http://www.links.org/files/decentralised-currencies.pdf)

Nakamoto S.: bitcoin:a peer-to-peer Electronic cash system. (http://www.bitcoin.org/bitcoin.pdf)