两种解决方案，一种高科技，一种低科技。

First the high-tech: The BOC offerings sell out in a seconds because bots get many of them in the first few milliseconds. So instead of trying to defeat the bots, sell them what they are scanning for: a bag of crap. Worthless crap, of course: bent paper clips and defiled photos of Rosie O'Donnell. Then have built-in random delays on the server for a few seconds at a time. As the sale continues, the actual value of the product sold will increase while the sell price does not. That way the first buyers (bots in the first few milliseconds) will get something worth much less than what they paid (brown onion cakes?), the next buyers (slower bots or faster humans) will get something unspectacular but worth the purchase price (bought on consignment?), and the last buyers (almost all humans) will get something worth more than the purchase price (break out champagne?). That flat-screen TV might be in the very last BOC purchased.

任何等待太久的人都会错过机会，但与此同时，任何购买太快的人也会吃亏。诀窍在于等待一段时间……但不要太多。这里面有一些运气，这是应该的。

低技术含量的解决方案是将中国银行的名称改为人类可以理解但机器人不能理解的名称。酒皮屎?装着臭味的麻袋?与各种商品相邻的拓扑平面?不要重复使用相同的名称，使用稍微不同的图片，并在产品描述中解释实际销售的产品。

两种解决方案，一种高科技，一种低科技。

First the high-tech: The BOC offerings sell out in a seconds because bots get many of them in the first few milliseconds. So instead of trying to defeat the bots, sell them what they are scanning for: a bag of crap. Worthless crap, of course: bent paper clips and defiled photos of Rosie O'Donnell. Then have built-in random delays on the server for a few seconds at a time. As the sale continues, the actual value of the product sold will increase while the sell price does not. That way the first buyers (bots in the first few milliseconds) will get something worth much less than what they paid (brown onion cakes?), the next buyers (slower bots or faster humans) will get something unspectacular but worth the purchase price (bought on consignment?), and the last buyers (almost all humans) will get something worth more than the purchase price (break out champagne?). That flat-screen TV might be in the very last BOC purchased.

任何等待太久的人都会错过机会，但与此同时，任何购买太快的人也会吃亏。诀窍在于等待一段时间……但不要太多。这里面有一些运气，这是应该的。

低技术含量的解决方案是将中国银行的名称改为人类可以理解但机器人不能理解的名称。酒皮屎?装着臭味的麻袋?与各种商品相邻的拓扑平面?不要重复使用相同的名称，使用稍微不同的图片，并在产品描述中解释实际销售的产品。

如何像SO那样实现captcha呢?

如果你正常使用这个网站，你可能永远不会看到它。如果你经常重载同一个页面，过快地连续发布评论，或者其他触发警报的事情，让他们证明他们是人。在您的情况下，这可能是不断地重新加载同一页面，快速地跟踪页面上的每个链接，或者快速地填写订单。

如果他们连续x次检查失败(比如2次或3次)，给该IP一个超时或其他类似的措施。然后在超时结束时，再次将它们转储回检查。

因为你有未注册的用户访问网站，所以你只有ip地址可以继续。如果愿意，您可以向每个浏览器发出会话并以这种方式跟踪。当然，如果连续(重新)创建了太多会话，还要进行人工检查(以防机器人不断删除cookie)。

至于发现太多无辜的人，你可以在人工检查页面上发布免责声明:“如果有太多匿名用户从同一位置查看我们的网站，也可能出现此页面。我们鼓励你注册或登录以避免这种情况。”(适当调整措辞。)

此外，X个人同时从一个IP加载同一页面的几率是多少?如果它们很高，也许你需要一个不同的触发机制来触发你的机器人警报。

编辑:另一种选择是，如果他们失败了太多次，而你对产品的需求有信心，阻止他们，让他们亲自打电话给你来消除阻碍。

让人们打电话似乎是一种愚蠢的措施，但它可以确保计算机后面有一个人。关键是要让块只在一个几乎不应该发生的情况下出现，除非它是一个机器人(例如，连续多次检查失败)。然后它强迫人类互动——拿起电话。

对于让他们打电话给我的评论，这里显然有一个权衡。你是否担心你的用户会在打折时接几个电话?如果我如此关心产品是否能被人类用户使用，我就必须做出这个决定，可能会在这个过程中牺牲(一小部分)我的时间。

既然你似乎决心不让机器人占据上风/抨击你的网站，我相信手机可能是一个不错的选择。因为我没有从你们的产品中获利，所以我没有兴趣接这些电话。然而，如果你分享一些利润，我可能会感兴趣。因为这是你的产品，你必须决定你有多关心和相应的实现。

其他释放阻塞的方式都不那么有效:超时(但他们会再次关闭你的网站，冲洗-重复)，长时间超时(如果真的有人试图购买你的产品，他们会被SOL并因检查失败而受到惩罚)，电子邮件(很容易由机器人完成)，传真(相同)，或蜗牛邮件(花费太长时间)。

当然，您也可以在每个IP每次超时时增加超时时间。只要确保你不是在不经意间惩罚真正的人类。

没有完全修复，但我在这里还没看到。

跟踪“砰”的地址，并张贴免责声明，说BOC/物品将不会被运送到任何不遵守你的TOS的地址。

这将对一些人产生心理影响，而其他想要利用您的站点的人将不得不切换方法，但您将否定他们的一个途径。

我想唯一能做的就是让努力超过垃圾邮件发送者的收益。所以这是一个“头脑风暴”的想法，我不知道如何实现的所有技术细节。我必须做一些研究，但根据我目前的知识，如果其他建议的方法被拒绝，就值得调查一下。

你已经在你的网站上使用flash，那么为什么不使用一个flash控件来协助或完成表单提交呢?控件可以使用密钥对或其他算法与web服务器进行加密通信来散列值?

我想整个形式可以在闪光?就我个人而言，我会使用Java小程序，因为那是我最喜欢的语言。

首先，让我回顾一下我们需要做的事情。我意识到我只是在转述最初的问题，但重要的是我们要百分之百地理解这个问题，因为有很多很好的建议，4个中有2个或3个是正确的，但正如我将演示的那样，您将需要一个多方面的方法来满足所有的需求。

要求1:摆脱“机器人抨击”:

首页的快速“猛击”正在损害网站的性能，这是问题的核心。这种“猛击”既来自单ip机器人，也可能来自僵尸网络。我们想把两者都去掉。

要求二:不要破坏用户体验:

我们可以通过实施一个讨厌的验证程序来有效地解决机器人的情况，比如打电话给操作员，解决一堆验证码，或类似的问题，但这就像强迫每个无辜的飞机乘客跳过疯狂的安全圈，只是为了抓住最愚蠢的恐怖分子的渺茫机会。哦，等等，我们真的这么做了。但让我们看看在woot.com上能否做到这一点。

要求三:避免“军备竞赛”

正如您所提到的，您不希望卷入垃圾邮件机器人军备竞赛。因此，您不能使用隐藏或混乱的表单字段、数学问题等简单的调整，因为它们本质上是可以简单地自动检测和规避的模糊度量。

需求4:挫败“警报”机器人:

这可能是您的要求中最困难的。即使我们可以进行有效的人类验证挑战，机器人仍然可以在你的首页上投票，并在有新报价时提醒编剧。我们也想让那些机器人变得不可行。这是第一个需求的更强版本，因为机器人不仅不能发出破坏性能的快速请求——它们甚至不能发出足够多的重复请求来及时向脚本人员发送“警报”以赢得报价。

好，让我们看看是否能满足这四个条件。首先，正如我提到的，没有一种测量方法能达到目的。你将不得不结合一些技巧来实现它，你将不得不忍受两个烦恼:

少数用户将被要求经历重重考验 少数用户将无法获得特别优惠

我知道这些都很烦人，但如果我们能让“小”的数字足够小，我希望你会同意利大于弊。

第一个措施:基于用户的节流:

这个很简单，我相信你已经做过了。如果用户已登录，并保持每秒刷新600次(或其他)，您将停止响应并告诉他冷却。事实上，你可能会更早地限制他的请求，但你明白我的意思。这样，一个登录的机器人将被禁止/节流一旦它开始投票你的网站。这是简单的部分。那些未经验证的机器人才是我们真正的问题，下面就来谈谈它们:

第二个措施:某种形式的知识产权限制，正如几乎所有人都建议的那样:

No matter what, you will have to do some IP based throttling to thwart the 'bot slamming'. Since it seems important to you to allow unauthenticated (non-logged-in) visitors to get the special offers, you only have IPs to go by initially, and although they're not perfect, they do work against single-IP bots. Botnets are a different beast, but I'll come back to those. For now, we will do some simple throttling to beat rapid-fire single-IP bots. The performance hit is negligable if you run the IP check before all other processing, use a proxy server for the throttling logic, and store the IPs in a memcached lookup-optimized tree structure.

第三种方法:用缓存的响应掩盖油门:

With rapid-fire single-IP bots throttled, we still have to address slow single-IP bots, ie. bots that are specifically tweaked to 'fly under the radar' by spacing requests slightly further apart than the throttling prevents. To instantly render slow single-IP bots useless, simply use the strategy suggested by abelenky: serve 10-minute-old cached pages to all IPs that have been spotted in the last 24 hours (or so). That way, every IP gets one 'chance' per day/hour/week (depending on the period you choose), and there will be no visible annoyance to real users who are just hitting 'reload', except that they don't win the offer. The beauty of this measure is that is also thwarts 'alarm bots', as long as they don't originate from a botnet. (I know you would probably prefer it if real users were allowed to refresh over and over, but there is no way to tell a refresh-spamming human from a request-spamming bot apart without a CAPTCHA or similar)

第四项措施:

You are right that CAPTCHAs hurt the user experience and should be avoided. However, in _one_ situation they can be your best friend: If you've designed a very restrictive system to thwart bots, that - because of its restrictiveness - also catches a number of false positives; then a CAPTCHA served as a last resort will allow those real users who get caught to slip by your throttling (thus avoiding annoying DoS situations). The sweet spot, of course, is when ALL the bots get caught in your net, while extremely few real users get bothered by the CAPTCHA. If you, when serving up the 10-minute-old cached pages, also offer an alternative, optional, CAPTCHA-verified 'front page refresher', then humans who really want to keep refreshing, can still do so without getting the old cached page, but at the cost of having to solve a CAPTCHA for each refresh. That is an annoyance, but an optional one just for the die-hard users, who tend to be more forgiving because they know they're gaming the system to improve their chances, and that improved chances don't come free.

第五种方法:诱饵废话:

Christopher Mahan had an idea that I rather liked, but I would put a different spin on it. Every time you are preparing a new offer, prepare two other 'offers' as well, that no human would pick, like a 12mm wingnut for $20. When the offer appears on the front page, put all three 'offers' in the same picture, with numbers corresponding to each offer. When the user/bot actually goes on to order the item, they will have to pick (a radio button) which offer they want, and since most bots would merely be guessing, in two out of three cases, the bots would be buying worthless junk. Naturally, this doesn't address 'alarm bots', and there is a (slim) chance that someone could build a bot that was able to pick the correct item. However, the risk of accidentally buying junk should make scripters turn entirely from the fully automated bots.

第六项措施:僵尸网络节流:

(删除)

Okay............ I've now spent most of my evening thinking about this, trying different approaches.... global delays.... cookie-based tokens.. queued serving... 'stranger throttling'.... And it just doesn't work. It doesn't. I realized the main reason why you hadn't accepted any answer yet was that noone had proposed a way to thwart a distributed/zombie net/botnet attack.... so I really wanted to crack it. I believe I cracked the botnet problem for authentication in a different thread, so I had high hopes for your problem as well. But my approach doesn't translate to this. You only have IPs to go by, and a large enough botnet doesn't reveal itself in any analysis based on IP addresses.

所以你知道了，第六小节是零。没什么。邮政编码。除非僵尸网络很小，或者足够快，可以被通常的IP限制，否则我不认为有任何有效的措施可以对抗僵尸网络，而不涉及明确的人类验证，如CAPTHAs。我很抱歉，但我认为结合以上五种方法是你最好的选择。你可能只需要abelenky的10分钟缓存技巧就可以了。