Effortless Eavesdropping費力竊聽

Are you worried that your intercepts are not quite as hi-fi as you hoped?您是否擔心您截取不太作為Hi - Fi的，因為你希望呢？ Can’t catch the details of other peoples’ electronic conversations?不能跟上的詳情，其他國家人民的'電子會話？ Your wiretaps letting you down?您的竊聽，讓您呢？ Welcome to the unfortunate world of the modern eavesdropper!歡迎不幸的世界現代eavesdropper ！

Computing and information scientists Eric Cronin, Micah Sherr and Matt Blaze of the University of Pennsylvania have investigated the reliability of current eavesdropping tools and found them to be lacking.電腦及資訊李家祥科學家克羅寧，彌迦sherr和馬特創新的賓夕法尼亞大學的調查的可靠性，目前的竊聽工具，並發現他們是缺乏。 “Obtaining ‘high fidelity’ transcripts is harder than previously assumed,” they say in a forthcoming issue of the International Journal of Security and Networks (2008, 3, 103-113). “獲得'高逼真度的'謄本，是比以前更難承擔， ”他們說，在即將出版的國際期刊的安全和網絡（ 2008年， 3 ， 103-113 ） 。 They add that, even in highly favorable situations those being spied on can block eavesdropping technologies and prevent messages from being reconstructed accurately.他們補充說，即使在高度有利的情況下，這些被間諜就可以攔截竊聽技術和防止信息被準確地重建。

Around one third of the systems tested report irregularities, and almost half incorrectly interpret covert text chosen by the sending party 大約有三分之一的系統測試報告違規情況，幾乎有一半不正確的解釋秘密案文所選擇的派遣黨

The team has tested both open source eavesdropping tools and commercially available packages, including Bro, Chaosreader, Ethereal, Snort, tcpick, tcptrace, tcpflow, CommView, NetworkActiv, and Sniffem.該小組已測試，均開放源代碼竊聽的工具和商業上可用的軟件包，包括人權法， chaosreader ，醚，嗤之以鼻， tcpick ， tcptrace ， tcpflow ， commview ， networkactiv ， sniffem 。

They point out that, unlike encryption or steganography (the art of adding a secret message to an image), preventing the accurate reconstruction of an intercepted communication (whether it be email, instant message, or VoIP), does not require the participation of the communicating parties -we’ll call them Alfie and Bess.他們指出，不同的加密或隱秘（藝術加入一個秘密的信息，圖片） ，防止準確的重建一截獲的通信（無論是電子郵件，即時訊息，或VoIP ） ，並不需要參與該溝通各方-我們將為稱他們為alfie與貝絲。 Indeed, simple unilateral eavesdropping countermeasures mean that electronic communications cannot be reconstructed with 100% fidelity by someone (Agent Clark, for instance) attempting to spy on Alfie and Bess.事實上，簡單的單方面竊聽對策意味著電子通信不能重建與100 ％富達由某人（代理人克拉克，例如）企圖以間諜對alfie與貝絲。

There are several properties of the internet that mean error-free eavesdropping is not nearly as easy as movie script-writers would have us believe.有幾個特性的互聯網意味著無差錯的竊聽是幾乎沒有一樣容易電影劇本-作家希望我們相信的。 First, there are many different components to any given communications connection.首先，有很多不同的組件，以任何特定的通訊連接。 Much of the control of the transfers that take place between Alfie and Bess’s internet communication devices is decentralized.大部分的控制權轉讓採取地方之間的alfie與貝絲的互聯網通信設備是分散的。 Moreover, when communication data is transferred it is done using a “best effort” approach, as opposed to a reliable and lossless method, resulting in reordered, duplicated, or lost packets.此外，當通信數據轉移，這是做了用“最大努力”的做法，反對以可靠和無損的方法，導致在重新排序，複製，或丟失的數據包。 These network effects make it difficult for Clark to perceive the communication in the same way as Alfie and Bess.這些網絡的影響，實在難以克拉克的看法，溝通，在同樣的方式alfie與貝絲。

The flow of data changes all the time, often asymmetrically, which makes getting a handle on the ebb and flow of data packets difficult among the billions of packets being routed to and fro along the same copper wires and fiber optic links.數據流的變化，所有的時間，往往不對稱，這就使得到處理就處於低潮，和流動的數據包難以之間的數十億包被路由和來來往往沿同一銅線和光纖的聯繫。 Additionally, there are ambiguities in the communications protocols, the way they are implemented and how they are configured, which again means reconstructing an electronic conversation from the various bits and pieces in a manner that is consistent with Alfie’s and Bess’ interpretation is difficult.此外，還有一些含糊不清之處，在通信協議，他們的手段實施，以及他們如何配置，這再次手段重建一個電子的談話從各種零碎以某種方式是一致的alfie的與貝絲'的解釋是困難的。 Finally, because there is an essential lack of sender and receiver authentication, there is no way for Clark to know for certain that any given thread of e-chat was sent by Alfie or Bess.最後，是因為有一個基本缺乏發送人及接收驗證，是沒有出路的，為克拉克知道了肯定的是，任何特定的線程電子商務的聊天，被送往由alfie或貝絲。

Moreover, if Alfie and Bess, or yet another third party, Evelyn, deliberately add confusion into the setup - either physically, using different broadcast frequencies on WiFi, or through software obfuscation - to rebuff the eavesdropper, then even without encryption Clark is all but locked out.此外，如果alfie與貝絲，或又一第三黨，伊夫林，故意混淆添加到安裝-無論是身體上，使用不同的廣播頻率對無線網絡連接，或通過軟件的困惑-抗擊ea vesdropper，那麼，即使沒有加密克拉克是所有，但鎖定。

Without using any confusion techniques, all but one of the eavesdropping packages were able to intercept and reconstruct the messages accurately.不使用任何混亂，技術，所有的，但其中的包被竊聽能夠攔截和重建的訊息準確。 However, as soon as confusion software was employed, all eavesdropping systems failed.不過，盡快混亂，軟件僱用，所有監聽系統的失敗。 The two simple confusion protocols against which the eavesdropping software was tested were MAC (as in the Media Access Control address that uniquely identifies devices connecting to a switch or hub) and TTL (time-to-live, the variable that drops packets if they stay in transit too long).兩個簡單的混亂議定書所針對的竊聽軟件進行測試，分別在Mac （如在媒體訪問控制地址唯一識別裝置連接到一個交換機或集線器）和TTL （時間到現場，變量下降的數據包，如果他們留在過境太長） 。 In MAC confusion, the address is spoofed or changed obscuring the source of any given packet, while exploiting TTL involves ensuring the packet last long enough to get from Alfie to Bess and vice versa but times out before Clark can grab it.在Mac混亂，地址是偽造的或改變模糊的來源，任何特定的數據包，而開發的TTL涉及確保數據包的長久足以讓從alfie ，以貝絲，反之亦然，但時代之前，克拉克可以抓住它。

Traditional wisdom has held that eavesdropping is sufficiently reliable as long as the communicating parties do not participate in a bilateral effort to conceal their messages,” the researchers say, “We have demonstrated that even in the absence of cooperation between the communicating endpoints, reliable internet eavesdropping is more difficult than simply capturing packets.” 傳統的智慧認為，竊聽是充分可靠的，只要有關各方溝通，不參加在雙邊努力掩飾他們的訊息， “研究人員說， ”我們已經表明，即使在沒有之間的合作溝通的端點，可靠的互聯網竊聽是比較難，比簡單地捕捉數據包“ 。

For more on the current debacle regarding National Security Agency allegedly eavesdropping on your email check out this security如需了解更多關於目前的崩潰就國家安全局監聽，據稱對您的電子郵件請參閱此安全 post郵政 from Surveillance State’s Chris Soghoian.從監視國家的克里斯soghoian 。