{"id":140,"date":"2008-02-11T00:20:29","date_gmt":"2008-02-11T08:20:29","guid":{"rendered":"http:\/\/cubist.cs.washington.edu\/Security\/2008\/02\/11\/security-review-pop-machines\/"},"modified":"2008-02-11T00:20:29","modified_gmt":"2008-02-11T08:20:29","slug":"security-review-pop-machines","status":"publish","type":"post","link":"https:\/\/secblog.cs.washington.edu\/Security\/2008\/02\/11\/security-review-pop-machines\/","title":{"rendered":"Security Review: Pop Machines"},"content":{"rendered":"<p>While we have access to reasonably priced soda in the ACM lounge or the Benson store, the average person looking for a convenient drink has to shell out between $1.75 and $2 to buy from a pop machine.\u00a0 But why pay if you don&#8217;t have to?\u00a0 It is obvious that the manufacturers of these machines have put thought into their security: most machines will hardly let you reach in for the drink you bought, let alone reaching up into the machine.\u00a0 Despite this, it is still possible to manipulate the machines into giving away drinks.\u00a0 Is their security good enough for most situations?\u00a0 Is the security too good?\u00a0 Let&#8217;s find out&#8230;<\/p>\n<p><!--more--><\/p>\n<p><strong>Assets<\/strong><\/p>\n<ul>\n<li>\u00a0Profits for the pop machine&#8217;s owner.\u00a0 Costs associated with security features on the machine are deducted from this.<\/li>\n<li>Customer satisfaction.\u00a0 A buyer should get at least what they paid for, hopefully not more.<\/li>\n<li>Ease of use.\u00a0 The machine should be simple to buy from or both of the above assets will be threatened.\u00a0 It should also be efficient to stock with more drinks for the same reason.<\/li>\n<\/ul>\n<p><strong>Potential Adversaries\/Threats<\/strong><\/p>\n<ul>\n<li>\u00a0Freeloaders and bored kids.\u00a0 These are the people trying to get more than they pay for, so are obviously bad for business.<\/li>\n<li>Power outages.\u00a0 The machine can&#8217;t rely on being powered to provide security.\u00a0 The outage might be environmental or caused by pulling the power cord.<\/li>\n<li>Determined criminal.\u00a0 These guys might take a free drink, but what they really want is all that money that&#8217;s sitting in the machine.<\/li>\n<\/ul>\n<p><strong>Weaknesses<\/strong><\/p>\n<ul>\n<li>The drink exit hatch.\u00a0 If something can come out, then something could potentially go in.\u00a0 This is usually the most obviously protected part of any machine.<\/li>\n<li>Mechanics of the delivery system.\u00a0 Not only do these have to be reliable under normal conditions, they should be resistant to strange conditions such as being tipped sideways, hit with a baseball bat, etc.\u00a0 A failed mechanical system\u00a0 could (at worst for the buyer) not deliver the paid-for drink or (at worst for the owner) spill out free cans of soda.<\/li>\n<\/ul>\n<p><strong>Defenses<\/strong><\/p>\n<ul>\n<li>\u00a0As we have all seen, the exit hatch can be protected by making it impossible to fit an arm or hand into.\u00a0 It should also be hard to insert any object like a coat hanger into the opening such that it can damage or manipulate the insides of the machine.\u00a0 This can be accomplished with one-way hatches up inside the machine that only let drinks out.<\/li>\n<li>Building the machine out of metal helps to protect against forceful attacks.\u00a0 Some machines today are made with clear glass or plastic displays.\u00a0 These can be nearly as protective as metal if the right materials are used.<\/li>\n<li>Just like pinball machines, pop machines might be fitted with tilt detectors.\u00a0 These can protect against a common attack that involves tilting a machine while it is delivering the drink such that the drink isn&#8217;t dispensed properly and the money is refunded.\u00a0 When another drink is bought you get both the improperly dispensed drink and another one for the price of one drink.<\/li>\n<li>Protecting the money in the machine requires multiple levels of security. It may be that the person who stocks the machine is different from the person who collects the money from it.\u00a0 These multiple levels include different sets of keys, and something like a mini safe to keep all the money in.\u00a0 On top of it all, the machine itself needs to be secured to the ground so it isn&#8217;t simply trucked away.<\/li>\n<\/ul>\n<p><strong>Conclusion<\/strong><\/p>\n<p>Pop machines are not especially secure since a determined person can usually get a free drink or two.\u00a0 From the standpoint of securing the money in the machine however, they are much more secure.\u00a0 Though they are less secure than an ATM, they hold much less money so a simpler and cheaper design can suffice.\u00a0 The main problem is providing a secure machine while allowing it to be easily used and reliable for the buyer.\u00a0 Assuming that the majority of buyers are honest, the amount of money lost to people who get free drinks can be ignored considering the large profit margin for soda.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>While we have access to reasonably priced soda in the ACM lounge or the Benson store, the average person looking for a convenient drink has to shell out between $1.75 and $2 to buy from a pop machine.\u00a0 But why &hellip; <a href=\"https:\/\/secblog.cs.washington.edu\/Security\/2008\/02\/11\/security-review-pop-machines\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":38,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-140","post","type-post","status-publish","format-standard","hentry","category-security-reviews"],"_links":{"self":[{"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/posts\/140","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/users\/38"}],"replies":[{"embeddable":true,"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/comments?post=140"}],"version-history":[{"count":0,"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/posts\/140\/revisions"}],"wp:attachment":[{"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/media?parent=140"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/categories?post=140"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/secblog.cs.washington.edu\/Security\/wp-json\/wp\/v2\/tags?post=140"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}