CTO Time: TEE Consensus

Dr. Wei, Trias CTO, will have a series of Trias Technology Sharing in Trias group( http://t.me/triaslab) from 10th Aug to 30th Aug, on every Monday & Thursday 12:00 GMT.

1. In the process of reaching a consensus, POA、IOTA、EOS, etc. all use the method of “reducing the number of nodes participating in consensus” to provide consensus efficiency. Taking POA as an example, they select verifiers they believe to be credible by means of legal constraints. How many advantages does the TEE mode chosen by Trias compare with the consensus mechanism of POA and EOS?

TEE limits the security of consensus node itself, and the security advantage is very obvious.

Neither POA nor EOS can remove the “people” factor. Even POW determines your rights based on the assets owned by the account. Our TEE completely relies on machines to calculate “the most difficult nodes to lie”, rather than relying on people to vote. This not only improves the security, but also reduces the number of consensus nodes.

2.What is the relationship between Trias TEE and TCB?

TEE is the trusted execution environment and TCB is the trusted computing base. The two concepts are different. TCB is a combination of hardware, firmware, software and responsible for executing security policies. It provides an additional environment for users to protect their environment.

TPM security chip is the implementation method of TCB. The chip in line with TPM must have the function of generating encryption and decryption key, and it must also be able to encrypt and decrypt at a high speed, and act as an auxiliary processor to protect BIOS and operating system from being modified. TPM security chip has the corresponding international standards, has a long history in academic construction, has experienced the test of long-term practice, is a kind of trusted chip that has been recognized. TCB is the authentication standard of node access in Trias. Only meets the strict high standard of TCB can it become a node of Trias.

3. Is Trias applied to SGX? What is the general principle of SGX?

Trias has been applied to SGX in the trusted execution environment (TEE). SGX provides a trusted execution environment called enclave.

It can prevent other applications, including operating system and BIOS system, from prying and tampering with the state of protected application and data in trusted environment. At the same time, SGX introduces the attestation authentication mechanism, encapsulates the logic of remote verification mechanism in the chip, and Intel or its agent responds to the request to verify whether the program and its results are credible. But at the same time, TEE will not only be applied to SGX technology, but also to Intel TXT, ARM, TrustZone and other multiple technologies as a guarantee.

4. Intel SGX (a kind of TEE) requires developers to use Intel’s SDK to refactor the code of conventional applications. Does this mean that if traditional applications want to access Trias platform, they must call Intel SGX’s SDK (or other SDK)?

TEE is only responsible for whether the state of consensus node is correct. Application access is related to contract and application layer, but not to TEE. Of course, we can consider binding TEE to the application in later development, just like mobile payment.

Mobile payment is usually run in TrustZone. However, in this case, the efficiency will be relatively low and the application development cost of users will be very high. Therefore, only the key links in the current conventional applications will be strongly bound to TEE. For example, Apple’s fingerprint unlocking and face recognition.

5. What is Trias’ gossip protocol?

Gossip is a decentralized, fault tolerant and consistent protocol.

Because services and data are distributed on different machines, each interaction between nodes is accompanied by network delay, network failure and other performance problems. Gossip is designed to solve these problems.

Gossip is a fault-tolerant algorithm with redundancy, and the final consistency algorithm. Although it is impossible to guarantee that all nodes are in the same state at a certain time, it can be guaranteed that “all nodes are consistent in the end,” the end is a point in time that exists in reality, but can not be proved theoretically.

Because Gossip does not require nodes to know all other nodes, it also has the feature of decentralization. Nodes are completely equal and no central nodes are needed. Gossip can be used in many fields that can accept “final consistency”: failure detection, route synchronization, Pub / Sub, dynamic load balancing.

Generally speaking, Trias uses the Gossip algorithm to complete the communication between nodes in the system. This algorithm is similar to the way of social network message transmission or epidemic disease transmission. It is based on peer-to-peer communication, and also known as Gossip algorithm.

It’s just like the way Gossip is passed through the crowd. Trias takes advantage of this feature to complete the authentication task of adjacent nodes. The existing theory and analysis of Gossip algorithm are based on sufficient mathematics. It has good scalability and robustness, and is well adapted to the decentralized, large-scale and highly dynamic distributed network environment.