Ethereum is the most popular decentralized application platform at present, which can handle complex intelligent contracts and realize untrusted transactions and applications, such as cryptocurrency transactions, mortgage loans, decentralized application management and so on. But at the same time, the security risks faced by Ethernet can not be ignored.

In the past few years, Ethereum network has suffered many attacks, such as DAO attack, odd-even multi-signature vulnerability and smart contract vulnerability. These attacks often lead to consequences ranging from light to heavy, such as the theft of tokens in contracts and the leakage of sensitive data stored in Ethereum due to misoperation.

In order to solve these problems, Ethereum developers have adopted various methods to ensure security, including:

1. Code review

The core code of Ethereum and the code of smart contract are open source. This means that anyone can check the code to find potential vulnerabilities and security problems. In addition, organizations such as the Ethereum Foundation will regularly review and test the code to ensure the quality and safety of the code.

2. Smart contracts

Smart contract is one of the core functions of Ethereum. Through smart contracts, users can deploy their own codes to Ethernet and realize their own business logic. Smart contracts are considered as a very safe way to manage transactions and assets, because the codes in the contracts are deterministic and cannot be tampered with.

3. Encryption technology

Ethereum network uses encryption technology to protect users' transaction data and assets. These technologies include public key encryption, hash function and digital signature. These technologies ensure the confidentiality and integrity of the transaction, but also ensure the authenticity and non-repudiation of the transaction.

4. Network security

Organizations such as the Ethereum Foundation will conduct regular network security tests to ensure the security of the network. In addition, they will also provide network scanning services to help users find vulnerabilities and security problems in networks and nodes. These tests and services ensure the security of the network and nodes, thus improving the confidence and usability of users.

To sum up, Ethereum is a relatively safe decentralized platform. Through code review, smart contract, encryption technology and network security, Ethereum is constantly improving network security. However, users still need to be cautious when trading and using the platform to avoid losses.