chain.php

// If you were looking for a way to describe a set of log messages, where
// each item contains the hash of the previous entry to build a chain, what
// would you call it?
//
// It's almost like a blockchain without the proof of work. I'm thinking as
// a security measure to prove that no items have been deleted

$seed = '52e2fb59e99dcd12528f92af25f401a6';

// Ignore the syntax and assume that $this->message points to the current
// array's message
$rootNode = [
  'msg' => 'This is the original message',
  'hash' => sha256($this->msg.$seed)
];

$node1 = [
  'msg' => 'Another message added',
  'hash' => sha256($this->msg.$rootNodeHash)
];