With so much R&D ongoing in the blockchain sector, it’s hard for any new tech to separate from the pack.
In addition to the sheer volume of designs for these new types of financial databases, separating the interesting ideas often requires ample peer review, testing and time. Still, this messy process hasn’t stopped tech giants like IBM and JP Morgan from conducting work that rivals the more well-known open-source creations like bitcoin and ethereum in aim and ambition.
While these contributions are grabbing headlines, however, praise across both open-source and enterprise communities has been rare.
Bucking this trend is Intel, which is winning support from even normally fickle technologists for its quieter, and some say, more innovative, approach to reimaging bitcoin’s tech for the enterprise.
One of the main contributors to this perception is proof-of-elapsed-time (PoET), a variation on the system that bitcoin uses to ensure that computers in the network agree about which transactions really took place, which it unveiled earlier this year. Perhaps better known to cryptographers, this high-tech tool solves the computing problem of “random leader election,” or selecting who will create the next block of transactions.
Despite the lack of attention it’s received, however, some veteran technologists consider PoET one of the more novel and radical proposals for how a blockchain network could achieve consensus.
Created by developers at Intel, PoET is notably designed to be used on a certain type of computer manufactured by the tech giant, called trusted execution environments (TEE).
On one hand, proponents argue that it’s a more environmentally friendly algorithm than bitcoin’s proof-of-work (PoW). On the other, many open-source developers are skeptical that could be widely used, since it requires trust in Intel.
Blockstream principal architect Christopher Allen, whose firm is a member of Hyperledger and one of the largest financial supports of bitcoin development, is one experienced observer that echoes this outlook.
Allen told CoinDesk:
“I’m actually not very impressed with Hyperledger Fabric and I think that Sawtooth Lake deserves more attention.”
Mix and match
One of the reasons Allen thinks so positively about Intel’s contribution is that it provides a variety of options and consensus algorithms, which he believes allow users to build a private blockchain to meets their needs.
“Sawtooth as a proof-of-concept demonstrates that you can have multiple consensus algorithms,” said Allen. “There’s no reason Sawtooth couldn’t do PoW or proof-of-stake.”
Allen mentioned that the working group has been discussing how to create the best architecture for allowing users to choose from a variety of consensus algorithms.
That’s where PoET comes in, as it’s one of the unique blockchain offerings that Sawtooth Lake makes available. Allen described it as a simulation of PoW that might be best used as an alternative for private blockchains.
Since it borrows from PoW’s Nakamoto-style consensus, PoET offers some benefits over Practical Byzantine Fault Tolerance (PBFT), a type of consensus algorithm used by Hyperledger, Stellar and others, he said. For one, it scales to a larger number of nodes and is more reliable since it works when larger numbers of nodes aren’t available.
One downside is settlement finality: users need to wait for a certain number of blocks before they can be fairly certain that their transaction will be recorded.
But, despite these unique properties, another perspective is that PoET doesn’t make sense for either private or public blockchains.
“It’s way too easy to create multiple layers of obfuscation that ultimately don’t contribute to the underlying security model,” said Bitcoin Core contributor Bryan Bishop.
Trust in Intel
The main critique to emerge is that participants would need to use Intel hardware like SGX to execute code in a protected area that can’t be inspected or tampered with.
That’s how you “know” — in theory — that the blocks filled with transactions will be dispensed at a certain interval, and that those transactions are correct. And you know that it can’t be tampered because of cryptography involved.
“PoET uses this special processor capability to regulate block frequency rather than computation,” Sawtooth Lake project manager Dan Middleton said, explaining that by using the protected area of the chip, the code is executed as designed.
“This is what enables the return to one-cpu-one-vote,” he continued, echoing an idea invoked in Satoshi Nakamoto’s bitcoin white paper.
But as for comparisons to PoW, there are notable differences. While PoW enables a trustless system, Bishop called Intel’s approach “trust-maximizing”.
That’s why both Bishop and Allen are skeptical that the consensus algorithm can be used for a public blockchain, like bitcoin or ethereum.
“It’s like giving the keys to the kingdom to Intel,” as Bishop put it.
“The participants are saying, ‘We trust Intel to not cause inflation of the system or otherwise interfere, and we believe Intel would rather shutdown before it would comply with government orders to disrupt a system that uses SGX,'” he said.
But while this probably isn’t good enough guarantee for decentralization advocates, this isn’t stopping Intel’s work from emerging as part of the conversation on the conference circuit.
Indeed, it may now be time for the wider market to assess how the idea could be evolved, for instance, for use on other processors.
As far as testing the protocol, a user doesn’t necessarily need to purchase a TEE. Middleton added that anyone interested in the protocol can now test how it commits blocks across a distributed network.
Allen contends that the use of TEE is why PoET isn’t currently as appealing as the more mature proof-of-work protocol, or maybe one day proof-of-stake, both protocols that enable participation via specific types of computer hardware.
But he agreed that if other hardware vendors implement the new algorithm, this could lead to other possibilities.
“It would be powerful to see a multi-vendor standard for PoET be created someday, for instance in the multi-vendor RISC-V consortium,” he said.
Like all ideas, it will be up to the market to decide. However, for now, it seems Intel’s work has passed one milestone, graduating to larger dicussion and consideration.
Interstellar image via Shutterstock