Shulou(Shulou.com)06/01 Report--

This article mainly introduces how to realize the encryption and protection of data on the Fabric chain of super books. It is very detailed and has a certain reference value. Interested friends must finish reading it!

1. Application background of Hyperledger Fabric chain code encryption / decryption.

In an enterprise environment, sometimes we need to deal with some sensitive data, such as storing credit card data, bank information, biometric data, health information, etc., which are part of our distributed ledger-based business applications. End users usually want to ensure the security of this private information even if the data is infiltrated.

In some traditional applications, we will encrypt the data in the database, so that even if someone sneaks into the database, they cannot understand the true meaning of the data. Similarly, encrypting the user data in the blockchain database is also an effective means to protect privacy. Now let's look at how to use NodeJS chain codes to encrypt the data to be written to the blockchain database.

Before we start the follow-up implementation, we need to point out that due to the introduction of additional encryption and decryption links, this will lead to slower application processing speed in the production environment, and the larger the amount of data to be encrypted / decrypted, the greater the impact on application performance.

2. The processing flow of Hyperledger Fabric chain code encryption / decryption

Before we start the encryption process, let's explain the logic of the chain code to be used. The example chain code is a simple user registration and login implementation. The user needs to provide a user name and password to register, and these identity information will be stored in the database in clear text. When the user logs in, the identity information saved in the database will be used for authentication. So we will add an encryption / decryption layer to these identities.

In this example, I'll try to keep the code simple, using nodejs's built-in crypto library. Depending on the application, you can also use custom encryption implementations.

The encryption method is implemented as follows:

Function encrypt (data,password) {const cipher = crypto.createCipher ('aes256', password); let encrypted = cipher.update (data,' utf8', 'hex'); encrypted + = cipher.final (' hex'); return encrypted;}

The encrypt () method encrypts the specified data using the aes256 algorithm, which takes two parameters:

Data: data to be encrypted

Password: encrypted password

The decryption method is implemented as follows:

Function decrypt (cipherData,password) {const decipher = crypto.createDecipher ('aes256', password); let decrypted = decipher.update (cipherData,' hex', 'utf8'); decrypted + = decipher.final (' utf8'); return decrypted.toString ();}

The decrypt () method decrypts the incoming encrypted data using the aes256 algorithm and the incoming encrypted password.

3. The implementation code of Hyperledger Fabric chain code encryption / decryption

We introduced the logic of the user registration / login chain code earlier. The user name and login password are submitted when the user registers, so we need to encrypt the user's identity data before storing it in the Hyperledger Fabric blockchain.

Async signUp (stub, args) {if (args.length! = 3) {return Buffer.from ('Incorrect number of arguments. Expecting 3');} else {console.info ('* * Storing Credentials on Blockchain**'); const credentials = {userName:args [0], password:args [1]}; let data = JSON.stringify (credentials); let cipher = encrypt (data,args [2]); await stub.putState (args [0], Buffer.from (JSON.stringify (cipher)); console.info ('* Signup Successfull..Your Username is'+ args [0])) Return Buffer.from ('Signup Successfull..Your Username is' + args [0]);}}

Similarly, when logging in, the chain code needs to verify that the user name exists in the database on the Hyperledger Fabric's chain and check that the password is correct. Therefore, before checking identity information, you need to decrypt the data on the chain of Hyperledger Fabric:

Async login (stub, args) {if (args.length! = 3) {return Buffer.from ('Incorrect number of arguments. Expecting 3');} let userName=args [0]; let password=args [1]; let credentialsAsBytes = await stub.getState (args [0]); if (! credentialsAsBytes | | credentialsAsBytes.toString () .length

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.