Creative Inventors

Word of the day: Alice, Bob and Eve

Alice and Bob are commonly-used names to represent Person A and Person B in security scenarios.In 1978, professors Ron Rivest, Adi Shamir and Len Adleman (RSA) chose the names Alice and Bob to make it easier for people to understand how public key encryption works.

They introduced the names Alice and Bob in a paper entitled "A Method for Obtaining Digital Signatures and Public-Key Cryptosystems." The names were intended to help people visualize how two entities could exchange information privately over an electronic mail system.Since that time, the names Alice and Bob have become standard placeholders for scenarios that involve untrusted communication channels.

For more complex security scenarios, Person C might be named Carol; Person D might be named Dave, and so on. Names for generic participants in the communication tend to follow a sequential alphabetic naming scheme, while names for significant participants are usually somewhat indicative of their roles.

Common characters from the large potential cast include:Charles - the certificate authority Eve - the eavesdropper Mallory - a malicious attacker Trudy - an intruder.The names Alice and Bob have become part of geek pop culture and can now be found in many science and math contexts, including programming, game theory, graph theory and physics.

Word of the day: content delivery network

A content delivery network (CDN) is an interconnected system of cache servers that use geographical proximity as a criteria for delivering Web content.

In a CDN, content exists as multiple copies on strategically dispersed servers. A large CDN can have thousands of servers around the globe, making it possible for the provider to send the same content to many requesting client computing devices efficiently and reliably -- even when bandwidth is limited or there are sudden spikes in demand. CDNs are especially well suited for delivering streaming audio, video, and Internet television (IPTV) programming, although an Internet service provider (ISP) may also use one to deliver static or dynamic Web pages.

CDN management software dynamically calculates which server is located nearest to the requesting client and delivers content based on those calculations. This not only eliminates the distance the content travels, but also reduces the number of hops a data packet must make. The result is less packet loss, optimized bandwidth and faster performance -- minimizing time-outs, latency and jitter, while improving overall user experience (UX). In the event of an Internet attack or malfunction at a junction of the Internet, content that's hosted on a CDN server will remain available to at least some users.