who are Alice and Bob??

Who are alice and bob?
That is the question...

The wikipedia article on the topic refers to placeholder names as  : "words that can refer to objects or people whose names are either temporarily forgotten, irrelevant, or unknown in the context in which it is being discussed"

So.. to put it bluntly,  Alice and Bob are our arbitrary heroes.

What other such arbitrary names do we use in our daily life?

1. Let's begin ( arbitrarily ) with : Alice and Bob - who are widely used names in the fields of physics and cryptography.
    
2. When it comes to legal documents and proceedings, the name most commonly used is John Doe, and lets not forget Jane, his female companion
    
3. And in mathematics, as we are all aware the, defacto name of an unknown variable is - x . ( the actual sequence in order of frequency of use of alphabets for naming variables is : x, y, a, b, z, c, p, q, r )
    
4. As far as words go, the most common name for a variable, function or constant is : "apple" ( http://drjim.0catch.com/hcii05-368-wordfrequency.pdf )
    
5. In the field of computing , the arch typical arbitrary words we use to represent variables, contants, functions or values when learning or demonstration concepts are foo and bar
    
6. And even before we move on to variables, who can forget the most common arbitrary string used the very first time we begin any programming language - "Hello, World"
    
7. Increasingly commonly, I've been not only seeing, but also adoptiong the replacement of foo and bar with "apple" and "sauce"
    
8. Andy Lester ( http://www.oreillynet.com/onlamp/blog/2004/03/the_worlds_two_worst_variable.html ) claims that the worst name most often used for a variable is - "data" . And the second worst ? - surprisingly enough : "data2"
    

And while we are on the topic of Alice and Bob, if you have time, you might want to read The Alice and Bob After Dinner Speech given at the Zurich Seminar, April 1984, by John Gordon, by invitation of Professor James Massey. ( http://downlode.org/Etext/alicebob.html ). It's a wee bit lengthy, but a nice humorous and light hearted attempt to understand the story behind cryptology's favorite heroes - Alice and Bob