Amazon has filed a US patent for a proof-of-work system that will use cryptography. The patent, filed on 14 May describes techniques for using the generation of Merkle trees as a solution to a proof-of-work challenge.
The challenge could be providing a solution to a problem, to a counterparty who is then able to verify the solution is correct. After the counterparty verified the solution, the party may then be able to obtain one or more computing resources.
In cryptography, a Merkle Tree is a tree where each leaf node is labelled with the hash of a data block and every non-leaf node is labeled with a cryptographic hash of the labels relating to its child nodes.The use of these ‘hash trees’ allows secure and efficient verification of the content of large data structures. Merkle Trees are used in the Bitcoin and Ethereum peer-to-peer networks.
According to the abstract of the patent:
“A proof-of-work system where a first party (e.g., a client computer system) may request access to a computing resource. A second party (e.g., a service provider) may determine a challenge that may be provided to the first party. A valid solution to the challenge may be generated and provided for the request to be fulfilled. The challenge may include a message and a seed, such that the seed may be used at least in part to cryptographically derive information that may be used to generate a solution to the challenge. A hash tree may be generated as of generating the solution.”
It seems like the new innovation could be used to protect a system from denial-of-service attacks and other actions from malicious entities.
“One way to mitigate against such attacks is to configure a service such that requests to the service incur some sort of expense, thereby providing a disincentive to participating in the attack. One such expense involves imposing a condition that a client submitting a request expend more computational resources (e.g., CPU cycles) to cause the request to be fulfilled. Other contexts also involve issues that are addressable, at least in part, through imposition of an expense in exchange for a service’s operation.”
Whilst the patent makes no specific reference to blockchain or cryptocurrency, it seems that the combination of Merkle Trees with a proof-of-work concept, could suggest that Amazon is moving towards further developments in this area.
Amazon has already made several advances in the world of blockchain. On 30 April it announced that its Amazon Web Services would launch a managed blockchain service to all of its users.
The product is designed to allow users to set up their own blockchain networks within their organisations. Using Ethereum and Hyperledger as its open source frameworks, Amazon claims that the new Amazon Managed Blockchain (AMB) can scale up to support millions of transactions if required.
In addition to this, Amazon subsidiary Whole Foods announced this week that it will now accept payments in Bitcoin, Ethereum, GUSD, and Bitcoin Cash.