Strong random generation

Code Comparison

// Default algorithm — may not be
// the strongest available
SecureRandom random =
    new SecureRandom();
byte[] bytes = new byte[32];
random.nextBytes(bytes);

// Platform's strongest algorithm
SecureRandom random =
    SecureRandom.getInstanceStrong();
byte[] bytes = new byte[32];
random.nextBytes(bytes);

Why the modern way wins

🛡️

Strongest available

Automatically selects the best algorithm for the platform.

📖

Explicit intent

Clearly communicates that strong randomness is required.

🔧

Configurable

Administrators can change the strong algorithm via security properties.

Old Approach

new SecureRandom()

Modern Approach

getInstanceStrong()

JDK Support

Strong random generation

Available

Widely available since JDK 9 (Sept 2017)

How it works

getInstanceStrong() returns the SecureRandom implementation configured as the strongest on the platform. This is controlled by the securerandom.strongAlgorithms security property.