BAEL-5641 How to Fix Slow SecureRandom Generator (#18897)

* BAEL-5641_add_sample_code

* BAEL-5641 add JHM benchmark

* BAEL-5641 parametrized version number in POM and formatting fix

Author: MBuczkowski2025

core-java-modules/core-java-security-2/pom.xml

@@ -24,11 +24,57 @@
             <artifactId>bcprov-jdk18on</artifactId>
             <version>${bouncycastle.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh-generator-annprocess.version}</version>
+            </dependency>
     </dependencies>
 
     <properties>
         <bouncycastle.version>1.76</bouncycastle.version>
         <commons-codec.version>1.16.0</commons-codec.version>
+        <jmh-core.version>1.37</jmh-core.version>
+        <jmh-generator-annprocess.version>1.37</jmh-generator-annprocess.version>
     </properties>
 
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>build-classpath</id>
+                        <goals>
+                            <goal>build-classpath</goal>
+                        </goals>
+                        <configuration>
+                            <includeScope>runtime</includeScope>
+                            <outputProperty>depClasspath</outputProperty>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>exec-maven-plugin</artifactId>
+                <configuration>
+                    <mainClass>BenchmarkRunner</mainClass>
+                    <systemProperties>
+                        <systemProperty>
+                            <key>java.class.path</key>
+                            <value>
+                                ${project.build.outputDirectory}${path.separator}${depClasspath}</value>
+                        </systemProperty>
+                    </systemProperties>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
 </project>

core-java-modules/core-java-security-2/src/main/java/com/baeldung/securerandomtester/SecureRandomAvailableAlgorithms.java

@@ -0,0 +1,23 @@
+package com.baeldung.securerandomtester;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+
+public class SecureRandomAvailableAlgorithms {
+
+    static String[] algorithmNames = { "NativePRNG", "NativePRNGBlocking", "NativePRNGNonBlocking", "PKCS11", "SHA1PRNG", "Windows-PRNG" };
+
+    public static void main(String[] args) {
+        for (int i = 0; i < algorithmNames.length; i++) {
+            String name = algorithmNames[i];
+            Boolean isAvailable = true;
+            try {
+                SecureRandom random = SecureRandom.getInstance(name);
+            } catch (NoSuchAlgorithmException e) {
+                isAvailable = false;
+            }
+
+            System.out.println("Algorithm " + name + (isAvailable ? " is" : " isn't") + " available");
+        }
+    }
+}

core-java-modules/core-java-security-2/src/main/java/com/baeldung/securerandomtester/SecureRandomPerformanceTest.java

@@ -0,0 +1,51 @@
+package com.baeldung.securerandomtester;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.concurrent.TimeUnit;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Level;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@State(Scope.Thread)
+public class SecureRandomPerformanceTest {
+
+    SecureRandom randomNativePRNGBlocking;
+    SecureRandom randomNativePRNGNonBlocking;
+
+    final int NBYTES = 256;
+    final int NSAMPLES = 20_000;
+
+    @Setup(Level.Trial)
+    public void setup() throws NoSuchAlgorithmException {
+        randomNativePRNGBlocking = SecureRandom.getInstance("NativePRNGBlocking");
+        randomNativePRNGNonBlocking = SecureRandom.getInstance("NativePRNGNonBlocking");
+    }
+
+    @Benchmark
+    public void measureTimePRNGBlocking() {
+        byte[] randomBytes = new byte[NBYTES];
+        for (int i = 0; i < NSAMPLES; i++) {
+            randomNativePRNGBlocking.nextBytes(randomBytes);
+        }
+    }
+
+    @Benchmark
+    public void measureTimePRNGNonBlocking() {
+        byte[] randomBytes = new byte[NBYTES];
+        for (int i = 0; i < NSAMPLES; i++) {
+            randomNativePRNGNonBlocking.nextBytes(randomBytes);
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        org.openjdk.jmh.Main.main(args);
+    }
+}