Cryptographically random data

// Create an array with a fixed size and type.
var array = new Uint8Array(5);

// Generate cryptographically random values
crypto.getRandomValues(array);

// Print the array to the console
console.log(array);

crypto.getRandomValues(array) can be used with instances of the following classes (described further in http://stackoverflow.com/documentation/javascript/417/binary-data#t=201607192101507088285) and will generate values from the given ranges (both ends inclusive):

• Int8Array: -27 to 27-1
• Uint8Array: 0 to 28-1
• Int16Array: -215 to 215-1
• Uint16Array: 0 to 216-1
• Int32Array: -231 to 231-1
• Uint32Array: 0 to 231-1