SPECTRECOIN V3 RELEASED w. 'Stealth Staking'
The Spectrecoin Foundation is thrilled to present the release of Spectrecoin v3.x with our novel ‘Proof-of-Anonymous-Stake’ protocol. This release has been nearly 10 months in development and testing and introduces the first fully anonymous staking system on a trustless setup. With this release, Spectrecoin introduces a 'Proof-of-Stake' protocol utilising ring-signatures in the staking transactions for the first time in any cryptocurrency.
In addition, there are other major changes in v3.x. The block time will increase to 96 seconds and the stake reward will be fixed per block. The reward for a block staked with SPECTRE (PoAS) will be 3 SPECTRE. The reward for a block staked with XSPEC (PoSv3), will be 2 XSPEC. This will slightly decrease inflation over time. You MUST update your wallet and reindex the blockchain or use the bootstrap method before the hard-fork which will be at the following time:
17/05/2019 (17th May 2019) 2000 GMT (UTC) London, UK time
2300 hours Moscow Standard Time (MSK) / Eastern European Time (EET)
1600 hours Eastern Daylight Time (EDT) US
Please read on below for an introduction to Spectrecoin 'Stealth Staking' also known as 'Proof-of-Anonymous-Stake' or PoAS.
STEALTH STAKING INTRODUCTION
The concept of 'Stealth Staking' has been bandied around for a while and there has been much speculation on how it might work. Well, our lead developer @Tek has done it. He has designed and implemented a unique anonymous staking protocol based on the well known PoSv3.
It can be argued that a privacy focused pure Proof-of-Stake cryptocurrency is not complete without a way to stake anonymously. There must be a way to maintain anonymity for the network participants throughout the staking process. As with any typical Proof-of-Stake cryptocurrency the staking transactions are UTXO based and are traceable and linkable on the blockchain. Your public address is linked to the UTXOs used in the staking transactions. Furthermore, all the staking transactions completed by the same user can normally be linked and users balances can be estimated, hence the ‘rich list’ feature of many block explorers.
Spectrecoin has therefore developed what we call ‘Proof-of-Stealth’ or to illustrate the difference with standard 'Proof-of-Stake', this is technically 'Proof-of-Anonymous-Stake’ which is a brand new and novel staking protocol utilising only anonymous SPECTRE in the staking transactions.
Spectrecoin v3 running on testnet.
In the screenshot above you can see a Spectrecoin V3 wallet running on the testnet staking with both XSPEC and SPECTRE and generating both XSPEC and SPECTRE respectively. The 'Development Contribution Blocks' are still generated as before regardless of how the block was created. If you are technically minded you can have a look at the testnet block explorer to see this in action.
If you are new to Spectrecoin, it is probably a good idea to go back and have a look at the current white paper (page 6 onwards in particular) that will explain the nature of the 'dual coin' system of Spectrecoin. A new and updated white paper will be released covering 'Proof-of-Stealth'.
What does all this mean to the users of Spectrecoin? It's simple really, it means that if you transfer your holdings to SPECTRE, our anonymous coin, nobody will be able to know your balance, nobody will know how much you stake and if you keep transactions SPECTRE <> SPECTRE you remain anonymous at all times. Looking for a slightly more technical explanation? Please see below.
How does 'Proof-of-Stealth' work?
In a standard staking transactions (PoSv3) a value known as the 'kernel hash' is calculated from several inputs including values taken from the last valid block, called a 'StakeModifier' and the value of the user's UTXO. A valid 'kernel hash' needs to be below a certain threshold that is determined by a separate calculation. The user (the wallet) who is able to generate a valid 'kernel hash' will be granted the right to add the next block to the block-chain. The newly added block includes the generated stake reward (XSPEC) and any transactions currently in the memory pool + any fees. The UTXO used to calculate the valid 'kernel hash' will be spent and the generated stake reward + the value of the spent UTXO will be included in a newly generated UTXO associated with the same public address. In this way every stake that has been generated as a result of UTXOs associated with a certain public address will forever be linked to that address and it's plain for all to see. Below is an example of standard staking transaction:
A standard staking transaction as explained above. The public address are visible.
In Spectrecoin's 'Proof-of-Stealth' the basic structure of the staking transactions and the rules remain mainly in tact. But, instead of using the UTXO value as an input in the 'kernel hash' calculation and the difficulty calculations, the so called 'keyimage' associated with an ATXO is used instead as an input to calculate the 'kernel hash' and difficulty. An ATXO is an 'Unspent Anonymous Transaction Output' and associated with a discreet SPECTRE value. SPECTRE takes on discreet values, like 100, 50, 40, 10, 1, 0.5 and so on. Each ATXO has a unique cryptographically determined 'keyimage' associated with it. This 'keyimage' can be used to prevent double spend and once an ATXO is spent the 'keyimage' is stored on the blockchain. The ATXO is totally dissociated from any user and as each and every ATXO is a unique 'data-entity', ATXOs cannot be linked to each other. Only the user holds the 'secret' key needed to prove ownership and no information is written to the block-chain that can in any way identify the owner of an ATXO. So, in order to spend an ATXO a user need to provide a valid ring-signature with a ring size of 10. The staking transaction therefore uses an ATXO as an input and new ATXOs are generated to the value of the stake reward in discreet units. See below for an illustration:
A 'proof-of-stealth' staking transaction with an input of 300 and an output of 300+0.01+0.001
Hence, in Spectrecoin's 'Proof-of-Stealth' both the initial calculations to find the 'kernel hash' and the subsequent staking transaction uses ATXOs only and neither the input nor the outputs can be linked to any user. Due to splitting and consolidation algorithms that we will explore in the upcoming white paper the 'transactional entropy' on the blockchain increases for every block. Basically, the privacy potential increases with every block and it will become increasingly difficult to analyse the blockchain over time as new anonymous SPECTRE gets spent and created.
What about the competition?
With the newly discovered Zerocoin vulnarability, we believe that Spectrecoin will be the ONLY cryptocurrency with anonymous staking once the new protocol gets activated on 17/05/2019. Spectrecoin's closest competitor in this area, PIVX has been left researching other privacy protocols and as far as we know their zPIV staking has been disabled. Spectrecoin therfore offers the best all-round privacy, anonymous transactions, fully integrated Tor and anonymous staking.