Protection against piracy

[alexandros]

Hello and Merry Christmas !
I have created a shareware application and i want to protect it against piracy.
I know there is Armadillo (http://www.siliconrealms.com) but it costs 300$ for Win32 only.
I plan to protect my software in a way and if i get enough sales then i will buy Armadillo.

I was thinking of using Triple DES encryption and a secret phrase #1 in order to generate a user key based on user name and machine name. Then the user sends the user key to me and i decrypt the user key and get the user name and machine name.
Then i encrypt again the user name and machine name by using Triple DES encryption and a secret phrase #2 and generate a registration key and send it to the user.

The user enters the registration key and at the start of the application,saving the project and at various points of the application i test if the registration key is valid. To do so i encrypt the user name and machine name using the secret phrase #2 and check if it matches the registration key.

The problem is that that the secret phrase #1 and secret phrase #2 has to be located in the source code. I will obfuscate ofcourse the code
but if a cracker finds the secret phrase it will be possible to create a key generator..

Also in order to make a trial version that works only 30 days i do the following:
The first time the application is run i create a registry key "First Run Date".
Each time the application exits i update a registry key called "Last Run Date".
If Current Computer Date <"First Run Date" -> Exit
If Current Computer Date <"Last Run Date" -> Exit
If Current Computer Date > "First Run Date"+30 days -> Exit.

What do you think of these ?
Is there any free protection system against piracy available ?

Thanks !
Alex