Thursday, January 31, 2008

Meeting: 30 JAN 2008 (w/ supervisor)

Session 1 Technical Report Review
ALAN checking with supervisor regarding the system flow diagram, use case diagram and content listings.

Below are the feedback from Supervisor :

System flowchart
- Should not have breakdown of function calls
- If there is input into a particular function, indicate it using text and arrow direction, do not use function block to indicate
- Advisable to include a brief explanation for the flow

CAPTCHA flow chart
- Change to sequence diagram
- include sequence number
- Advisable to include a brief explanation for the sequence

Use case diagram
- should have 2 users

*Customer
*Administrator for maintaining the product


OCR readings records acquired from product testing.
Sebastian checking with supervisor regarding which section of the technical report should we include the OCR reading result acquired from product testing.

OCR readings records can be either under
- Test plans
- Conclusions
- Product analysis


Brute force attack calculation.
Team checking with Supervisor regarding the brute force attack information.

Below are the calculation explained by Supervisor:
CAPTCHA text is formed by 8 characters with a choice of 46 characters in each position.

46 pow 8 = 20,047,612,231,936 sample space

To get brute force attack computation time required:

(sample space /2) . time taken

time taken = time needed by our system in order to validate a single end user’s answer.

Time taken is to the time needed by our system in order to validate a single end user’s answer.

Discuss with Supervisor regarding Session 1 presentation.
Supervisor reviewed the contents of team presentation slides and feedback :

- RUP methodology should be explained briefly.
- Highlight the differences between our CAPTCHA and those in the market
- Advisable to show the calculation of the brute force attack on our CAPTCHA.
- Advisable to explain the resources used to generate our CAPTCHA image
- Advisable to demo or show some OCR readings on our CAPTCHA
- Suggested using a wireless modem to provide access point to allow mobile phones to connect to.
- Advisable to provide handouts for final presentation


Progress Report submission by team leader
Sebastian submitted Progress Report for session 1 to Supervisor. Some of the suggestion by Supervisor regarding the report format.

- Advice to show our process base on gantt chart that we proposed in proposal.
- Advice to write a summary of what we have done in phase 1.
- Advice to write what we are going to do in phase 2.

Additional CAPTCHA design features suggestion.
LEXIS suggested include additional CAPTCHA feature which allow customers to edit the CAPTCHA design effects to suite their application. Supervisor has reviewed and will confirm with Adrian Choo to see whether the adding feature will be considers as part of the project scope or is the extra features.- Supervisor advice team to come out with a non-text based CAPTCHA in order to score high points.

New CAPTCHA design suggestion.
LEXIS suggested to design a animated CAPTCHA which require end users interaction. It requires end users to use the mouse pointer to point the path in order for an object X to move from A to B. In the meantime, there will be some objects like rock or tree which might block the object X from moving in a straight path. Hence it need end users to find a way in order to reach B which only human can do.

But this design will not be able to apply to mobile devices usage. Supervisor will confirm with Adrian Choo regarding the new design suggested which it only allows to run in computer platform.

Technical: MIDlet Session Handling

Found some example codes on Session Handling for MIDlet. 

Invoke the servlet...



Prints out the Session ID


This is rather last min and we have yet to fully understand the coding, thus we are not able to demo this portion in the end of Session 1 Presentation. 

Wednesday, January 30, 2008

Technical: JSP and Servlet Communication

The diagram below shows the best practices of JSP and Servlet communication implementation.

Tuesday, January 29, 2008

Updates: Captha Design v3.2

Symbols were added in to further increase the sample space. As we know certain symbols like "," and "." may look alike from certain angles/from additional background noises, we decided to choose 10 more obvious symbols to start up with. They are  { '!' , '@' , '#' , '$' , '%' , '^' , '&' , '*' , '=' , '?' }

Sunday, January 27, 2008

Technical: Captcha Breakdown Structure

Below is the detailed breaked down of the captcha structure.

Technical: MIDlet JDBC & mySQL

The CLDC framework do not support JDBC APIS. To connect to databases we can call a Servlet from the MIDLets. Connection to database, running the queries and other functionalities have to be be implemented in the Servlet. The MIDlet passes the parameters like username, password in a string throught a DataOutputStream to servlet

Tuesday, January 22, 2008

Updates: Captcha Design v3.1

To tackle the bad design of the previous version, modifications are done by replacing the usage of random range of angles of values -45 to 45 degrees to randomly select 4 fixed different angles degrees. 


At least now we wouldn't have to worry about characters going upsize down/off sight.