Hellar: PeertoPeer CryptoCurrency with Anonymous Blockchain Transactions and an Improved ProofofWork System
7 May 2023
Hellar is the privacy centric cryptographic currency based on Satoshi Nakamoto’s Bitcoin. Hellarpay, a technology for sending anonymous block transactions is incorporated directly into the client using extensions to the core protocol. An improved proofofwork using a chain of hashing algorithms replaces the SHA256 algorithm and will result in a slower encroachment of more advanced mining technologies (such as ASIC devices). DarkGravityWave is implemented to provide quick response to large mining power fluctuations.
Bitcoin was a remarkable invention. The concept of proofofwork allowed, for the first time, decentralized consensus on a large scale network with no central authority. However, due to the very nature of decentralization, the blockchain is inherently not private. This has obvious implications for users' personal privacy, as all transactions are traceable in the block chain.
To solve this inherent problem of privacy, we created a new cryptocurrency: Hellar.
Hellar uses a decentralized implementation of CoinJoin in order to anonymize transactions. We named this implementation " Hellarpay".
Hellarpay is a CoinJoinbased, decentralized peertopeer being implemented into Hellar. Hellarpay provides protocol extensions to merge transactions together into larger anonymous transactions. This system uses regular nodes and elects a master node to create the transaction in a decentralized fashion.
Hellarpay is a completely trustless solution, where users can achieve a high level of anonymity. With the exception of a collateral transaction (which will be explained in detail later), users run no risk of losing any money at any time.
This implementation of Hellarpay is optionally available through the client and can be deactivated at any time if a user wishes.
Hellarpay is available as an option through the client and can be deactivated by the user at any time. The Hellarpay implementation gathers the required transaction information in multiple stages within each session:
A scheme using blind signatures is implemented to prove the provided outputs belong to one of the participants of the pool. Using this strategy neither the master nor other nodes know which outputs belong to which inputs.
With the decentralized implementation of Hellarpay, there are inherent challenges to dealing with rogue users who intend (or attempt) to attack the system. Such users could modify the software in a way that would cause it to refuse to sign, which would force the pool to reset every session.
To defend against various attacks, Hellarpay implements a collateral system. A transaction for 0.1HEL is made out to the payment node to ensure proper usage of the system. This transaction is separate from the funds added to the Hellarpay pool. If a user submits an input but refuses to sign or leaves at any stage, the payment node will “cash” the transaction by signing and broadcasting it. Collateral transactions require multiple signatures to complete from more than one payment node.
Payment nodes are simply the last node to create a block specifically, the last block solver and the one before that. These nodes will monitor Hellarpay for misbehavior. Should any be discovered, the payment nodes will “cash” the transaction by signing and broadcasting it. This has the added benefit of creating a sustainable income stream in addition to mining for miners, while simultaneously protecting the network from attackers.
The collateral transaction is made to multiple payment nodes. Cashing collateral transactions require multiple signatures from the user, payment node 1 and payment node 2.
Collateral forfeited to the network will be paid to the payment nodes, which are the last two nodes to solve a block. These nodes will commonly be the pools. To cash the collateral transactions and take all of the money, multiple pool operators would be required to collude. In that case the pools users would learn of this and stop using that pool.
Collateral transactions from a successful Hellarpay session are effectively destroyed using a sigScript to make them valid only for a given period of time.
An anonymity enhancement to the generic CoinJoin implementation is added by only allowing inputs of the same size into the Hellarpay pools. These sizes are referred to as “denominations” and are in powers of ten (for example, 1HEL, 10HEL, 100HEL, 1000HEL). This allows the inputs from all users to be virtually the same. Outputs per user must add up to the denomination size.
