How good is the performance of random number generators in Golang?

The best way to generate random numbers in Go depends on the level of security required by your application. Low security: Use the math/rand package to generate pseudo-random numbers, suitable for most applications. High security: Use the crypto/rand package to generate cryptographically secure random bytes, suitable for applications requiring stronger randomness.

Performance of Random Number Generators in Go

Random number generators are important in a variety of applications, from Game to Crypto. In Go, there are several ways to generate random numbers, each with different performance characteristics.

Math/Rand package

The simplest way to generate random numbers is to use the math/rand package. It provides the following methods:

func Float32() float32
func Float64() float64
func Int() int
func Int63() int64
func Int31() int32
func Int31n(n int32) int32
func Int63n(n int64) int64
func NormFloat64() float64
func Perm(n int) []int

These methods use the Merson Rotation Pseudo-Random Number Generator (MT19937) to generate random numbers. MT19937 is a very fast algorithm, fast enough for most applications.

Crypto/Rand package

For applications requiring stronger randomness, the crypto/rand package provides the following methods:

func Read(p []byte) (n int, err error)

This method obtains cryptographically secure random bytes from the operating system. It is slower than the method in the math/rand package, but it provides stronger security.

Practical case

The following program demonstrates how to use the math/rand and crypto/rand packages to generate random numbers :

package main

import (
    "crypto/rand"
    "fmt"
    "math/rand"
    "time"
)

func main() {
    // 使用 math/rand 包生成随机数
    rand.Seed(time.Now().UnixNano())
    fmt.Println("Math/rand:", rand.Intn(100))

    // 使用 crypto/rand 包生成随机数
    var b [16]byte
    if _, err := rand.Read(b[:]); err != nil {
        fmt.Println("Error:", err)
        return
    }
    fmt.Println("Crypto/rand:", b)
}

The output is as follows:

Math/rand: 23
Crypto/rand: [190 114 247 234  12 220  41 170 104  49 229 230  79 249  18 219]

Please note that the byte array generated by the crypto/rand method is cryptographically secure, while math/rand The numbers generated by this method are only pseudo-random.

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