A proof of work is a piece of data which is difficult to produce but easy for others to verify and which satisfies certain requirements. Producing a proof of work can be a random process with low probability so that a lot of trial and error is required on average before a valid proof of work is generated.

When folks in blockchain/crypto space hear PoW (proof-of-work) they immediately think of Bitcoin's PoW and assume that all PoWs are costly and time consuming. This is not true. PoWs can be cheap and less time consuming.

In this article, we will discuss about a new PoW by Uniris, that is very cheap and less to no time is consumed during the PoW. This PoW adds another layer of security. The PoW is done inside the ARCH Consensus during the transaction validation.  


Overview

The Bitcoin and other networks based on the principle of Proof of Work (PoW) ensure an unpredictable and pseudo-random election of the nodes in charge of the validation of the blocks (mining). They also ensure that the network remains synchronous and that each node will have time to recover the previous blocks, thanks to the time required to calculate this proof of work (10min).

In Uniris network:

  • The election of the unpredictable and pseudo-random validation nodes is ensured by the Heuristic Validation Algorithms.
  • The synchronization of the data is ensured by the Heuristic Algorithms for replication of data, which provide the knowledge of the nodes responsible for storing a given transaction chain, at all times.
  • The proof of work mechanism (discussed below)

Background

Every Transaction contains the below (Read Transactions Chains for more info)

What does a Transaction Contain?

'OriginKey Sig' is a signature from the private key associated with the device or software from which the transaction was generated.

Verifying this 'OriginKey Sig' is the PoW by Uniris


PoW Mechanism

The Proof of Work consists of finding the right public key associated with the signature of the device (OriginKey Sig) of the transaction. This involves a search on a finite set of public keys ensuring that the device is definitely authorized to generate the transaction and that, at the same time, the nodes able to find that the key are authorized.

There can be many different devices in the Uniris Network like Software devices, Biometric devices, usb key devices, etc. Each family of devices have their own list in their own Transaction Chain independent of other family of devices.

A brute force search may take a considerable amount of time and close to impossible.

This mechanism makes it possible to support an unlimited number of devices while guaranteeing the confidentiality of the user with respect to the device used, the private key used by a device being the last key shared between the devices of the same family (software keys, smartphone keys, smart card keys, etc.). Each device will have its own transaction chain allowing it to update its keys.

The network can ban a particular device if the device is malicious.


Conclusion

The PoW is maintained to ensure the authentication of the transaction origination devices. This allows additional security requirements on transaction validation like:

  • prohibit any transaction in case of key theft.
  • allow user to check his/her balance on any smartphone while generate a transaction only in his/her smartphone.
  • enable the organizers of an election to ensure the actual biometric identity of a voter by the associated cryptographic identification of a particular device.
  • many more....