The Da Vinci Webquest on Dan Brown's Official Website answers

The Da Vinci Webquest is an online puzzle.
I just completed it and will explain to you how to solve this
You can access the website through this link
Lets start

1. Go to the link
2. On the question please type da vinci's given name type LEONARDO
3. If you move the cursor over the text then words will unscramble.Google "famous fresco in milan", you will find The Last Supper to be the answer.
4. When the first gate appears copy and paste the message to any word processor and the message will appear :

               Well done, my friend, I sense your heart is true.
               You now have earned the right to your next clue:
               The Mona Lisa's dwelling once housed kings.
              A lavish Paris palace with three wings.
              One wing is Sully... one is Richelieu.
              Please name the third (I've mentioned only two).

         Using google search, you will find the answer to the third gate to be DENON.

Next gate appears .Click on the hint and you will find how to decipher the sentence below -

WTRGOWTRDTWOLOCDBANOOENDM
 
This whole sentence consists of 25 letters.The metod of encoding used is the caeser's square.(Which you will understand if you read 'Digital Fortress')Here since 5 x 5 = 25 (or square root of 25 is 5)
simply make groups of five letters and put them one below the other.

W T R G O
W T R D T
W O L O C
D B A N O
O E N D M

Read this vertically to get-
wwwdotrobertlangdondotcom
or
www.robertlangdon.com

Type this in the address bar .Go to the website.

Go through the website as it will help you in the later gates

To get to the third gate you have to click on the mail icon with the label 'contact'

Send an email to robertlangdonquestions@gmail.com.

This is his reply-

Thank you for writing. I apologize for this automated
response, but I am currently in Florence attempting
to locate the key to "The Prophecy" - an encoded
parchment that may have been written by Leonardo Da
Vinci. I will respond to your message upon my return.

Sincerely,

Robert Langdon

Jonas,

If this is you, DON'T erase this email - I can only
send it once. Something terrible has happened. I was
attacked outside my hotel, and the parchment was
stolen! I think the thieves intend to auction it on-
line. I don't have reliable web access here, and I
need your help. You must find this auction
immediately and track down the parchment. Here are
the two best art-related auction sites:

http://www.auctionport.com
www.relic-bay.com


When you search, you should definitely include the
initials "LSPDV" because they are so rare. Please do
everything in your power to locate the parchment
soon - I must get it back. I'm getting very close to
uncovering the key to the code.

- Robert

Go to the second link.


When you enter the site you will be asked to type keywords related to the relics you are seeking.
Type 'LSPDV'

Click on 'Click to view item'

The buyer has written that she has put the parchment in to safekeeping to a bank advertised on this very site.Tis gives us a clue that we should click on the advertisement of  the 'Depository Bank Of Zurich'.

Type the name Marie Denarnaud to login.
When asked for the account number click on the hint that Marie left for herself.
It states -
Marie, your father (knowing how much you love books about Da Vinci) gave you that new American novel The Da Vinci Code. For your account number, look at the middle of Chapter 44.
The account number is actually the Fibonacci series.
The pattern of the series is

1
1
1 + 1 = 2
1 + 2 = 3
2 + 3 = 5
3 + 5 = 8
5 + 8 = 13
8 + 13 = 21

and so on...

Each number is the sum of the previous two numbers.

The bank account number is 1123581321.

Instead of the parchment you will find a message from the police that says


Dear Mademoiselle Marie Denarnaud,
I regret to inform you that we have impounded the contents of your box. The parchment you purchased on-line was stolen. It belongs to a U.S. symbologist, Robert Langdon. We have been unable to reach Mr. Langdon directly, but we have returned his parchment to him in care of his editor Jonas Faukman at the Doubleknight Publishing Group in New York. Mr. Faukman anticipates your concern and is eager to speak to you at your earliest convenience. He can be reached in his office at (212) 782-9920. He urged you to phone him regardless of the hour.

If you dial the number you will hear a voice saying that he is out of his office and asks you to visit his site www.doubleknightbooks.com.


Click on 'enter our site' and then click on 'employee message board.'
Type 'Jonas Faukman' when asked for employee name.

You don't know the password so the only way you can know is send and email to him.
His email ID is jfaukman.doubleknightbooks@gmail.com

This is his reply-

Thank you for your inquiry. I’m currently editing out
of the office but I’ll get back to you as soon as
return. Robert, if this is you please leave me a
message on our employee message board (use
my name to login). I’ve reset the password to
something we both know – the name of the city
where we had our photo taken together recently.
-Jonas Faukman

[ATTENTION: Due to routine maintenance of the
Doubleknight website, this message will be the only
response you receive from this employee today.]


The photo Faukman is referring to is the photo at Robert Langdon's site.
Go visit it again.

The password is venice.

enter the doubleknight's site and type the password.one message titled jonas i've got the key will give you a link- robertlangdon.com/secretpage.htm

You have to type his robert's favourite symbol .
its,if you dont know ankh.

Breaking the code.Each letter has its own enclosure.I'll leave it to you to break the code.anyways the prophecy is the truth will be told in 2003. (the year da vinci code was published)

You will receive a phone number .dial it and you will hear a congratulation message from dan brown