Pilot Handwriting .com. How to Sync an iPod. How To Bypass Internet Censorship. Facebook Data Center FAQ. With more than 900 million active users, Facebook is the busiest site on the Internet and has built an extensive infrastructure to support this rapid growth. The social networking site was launched in February 2004, initially out of Facebook founder Mark Zuckerberg’s dorm room at Harvard University and using a single server. The company’s web servers and storage units are now housed in data centers around the country. Each data center houses thousands of computer servers, which are networked together and linked to the outside world through fiber optic cables. Every time you share information on Facebook, the servers in these data centers receive the information and distribute it to your network of friends. We’ve written a lot about Facebook’s infrastructure, and have compiled this information into a series of Frequently Asked Questions.
How Big is Facebook’s Internet Infrastructure? What is a Digital Signature? Bob has been given two keys. One of Bob's keys is called a Public Key, the other is called a Private Key. Bob's Public key is available to anyone who needs it, but he keeps his Private Key to himself. Keys are used to encrypt information. Encrypting information means "scrambling it up", so that only a person with the appropriate key can make it readable again.
Susan (shown below) can encrypt a message using Bob's Public Key. With his private key and the right software, Bob can put digital signatures on documents and other data. Bob's software then encrypts the message digest with his private key. Finally, Bob's software appends the digital signature to document. Bob now passes the document on to Pat. Plot complication... It just so happens that Susan works at the company's certificate authority center. Now Bob's co-workers can check Bob's trusted certificate to make sure that his public key truly belongs to him. Let's say that Bob sends a signed document to Pat.