WordPress - onetime nonce (see: www.stephenharris.info/2013/nonces-that-are-used-only-once/ )

onetime_nonce.php

<?php
function create_onetime_nonce( $action = -1 ) {
	$time = time();
	$nonce = wp_create_nonce( $time . $action );
	set_transient( '_nonce_' . $time, 1, 60*60 ); // adjust the lifetime of the transient
	return $nonce . '-' . $time;
}

function verify_onetime_nonce( $_nonce, $action = -1 ) {
	@list( $nonce, $time ) = explode( '-', $_nonce );
	
	// bad formatted onetime-nonce
	if ( empty( $nonce ) || empty( $time ) )
		return false;
	
	$nonce_transient = get_transient( '_nonce_' . $time );
	
	// nonce cannot be validated or has expired or was already used
	if (
		! wp_verify_nonce( $nonce, $time . $action ) ||
		false === $nonce_transient ||
		'used' === $nonce_transient
	)
		return false;
	
	// mark this nonce as used
	set_transient( '_nonce_' . $time, 'used', 60*60 );
	
	// return true to mark this nonce as valid
	return true;
}