Speed vs. Security: The Impact of Faster Protocols on the Web
In recent years, data speed has become increasingly important. The quality of the material available on the Web, such as the ongoing improvements in video resolution, has resulted in a greater amount of data being sent across the internet than ever before. This, of course, drives a need for faster internet. One such response to this need is to make the actual protocols that drive the Web faster. According to the article, one such protocol being designed is QUIC, based off of UDP instead of TCP, two methods of transferring data on the internet.
To appreciate the difference here, it is important to understand the difference between UDP and TCP. TCP establishes a connection between the sender and the receiver, ensuring that all data sent arrives correctly. This makes it reliable, but also slow. UDP, on the other hand, establishes no such connection; data is sent, and however it arrives is what the receiver gets. If there was an error in transmission because of some kind of interference or other factor and the data becomes unrecoverable, it is lost. However, because no confirmation of correctness is needed, UDP is much faster than TCP. Traditionally, Web pages are sent over TCP because of the reliability, but if protocols such as QUIC can result in data being sent over UDP both quickly and reliably, it would be a great boon to the internet.
However, the article raises the important counterpoint to using UDP: security. In a similar manner as we described the Web having hubs that have links to pages, underlying the Web are servers that distribute Web pages. These servers are what Web traffic passes through. Thus, these machines necessarily have much higher bandwidth than any end user of the Web. Still, it is possible to overwhelm a server; the act of intentionally sending incredible amounts of traffic to a single server to disable it is known as a DoS (denial of service) attack. If a user wishes to perform such an attack, he must be able to send more data than the server can handle; this is often done by coordinating a large number of computers to perform an attack simultaneously.
However, there exists another avenue of attack based off of UDP. If a particularly large server has certain vulnerabilities, it could be commanded to send a stream of UDP data to a server with a single input packet. This is known as amplification. By doing this, it is not necessary to get large numbers of computers to perform a DoS attack. Instead, one can send a modest amount of packets to a server with this vulnerability, and that server will then send hundreds of times more packets to the target server.
Why is this related to the speedy protocols? A server owner can block traffic from reaching his server; thus, he can prevent such amplification attacks by blocking UDP traffic. However, if protocols such as QUIC become prevalent, UDP traffic will need to be allowed into the server, which opens it to being the target of an amplification attack. This is the trade-off presented in the article; we can attain higher speeds of transfer, but we become more vulnerable to attack.
Thus, as we advance the Web in capability, we also make it more likely to be damaged. Indeed, large swaths of the Web can go down if the correct servers are attacked; a recent attack on a DNS company, Dyn, brought down Twitter, SoundCloud, Spotify, and other such major sites. When this happens, we can picture this as removing nodes from the graph representing the Web, as discussed in class. Removing these nodes also then removes edges leading to and from the node, reducing the number of paths available on the internet. We can imagine, then, that if many pages on the Web are taken down, it makes it very hard to navigate from one site to another. Given the majority of users navigate the Web in this way by following links, the average user will be greatly impeded if a hub site they use goes down. Thus, because of the Web’s strongly connected nature, whenever one part of it goes down, hundreds of sites are hurt alongside it from loss of views, sales, or ad revenue. We must keep in mind then, as we implement new speedy protocols to respond to the increase in demand for high quality content, that we must keep the Web secure against such devastating attacks, or vast numbers could be hurt worldwide in the collateral damage.