1. CS122B: Projects in Databases and Web Applications Winter 2017
Notes 04: Domain Registration and reCaptcha
Professor Chen Li
Department of Computer Science
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2. Motivation Register a domain name for people to remember
More flexibility to change the IP address(es)
If we change the IP address, as long as the domain name is mapped to the new address, we are good
Important for marketing and sales
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3. Steps Go to a domain registrar site such as GoDaddy
Search for a good, available domain name
Purchase it!
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4. A good domain name is important!
People tend to remember meaningful names, even if they are long: CarsInIrvine.com
Try to avoid weird acronyms
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5. Domain Parking
“Registration of an internet domain name without that domain being associated with any services”
For sale
For ads
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6. Mapping domain to IP Example: cs122b.com
I purchased it from Godaddy.com
Modify its zone file to map it to my AWS instance
For now on I can access cs122b.com instead of ec XXX-XX.us-west-2.compute.amazonaws.com 
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7. reCaptcha: preventing internet bots
Web sites have valuable information
Example: ticketmaster.com
“Bad people” write programs/bots to send bad requests (e.g., registration, buying tickets)
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8. First version: captcha
Use Captcha to correct OCR errors
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9. 2nd version: recaptcha
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10. reCaptcha example: TomcatFormReCaptcha.war
index.html
3. g-recaptcha-response
Client Browser
Tomcat Server
2. g-recaptcha-response
4. g-recaptcha-response
Secret Key
1. Site Key
Google reCaptcha
Server
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