shareware / software copy protection
Alan B. Pearce email (remove spam text)
>Most of these solutions are based on public key encryptions. You
>send a data to the dongle, and the dongle encrypts it or sign it
>with the private key and sends back the results so the software
>of yours can check it using the public key.
But you missed my point that I was making in the bit you quoted.
My understanding of Dwaynes situation is this.
He has data that he wishes to manipulate to send to a milling machine to
make a 1 off PCB.
He manipulates this data using a program on a PC, to generate the necessary
data stream to drive the mill.
By sending the manipulated data from the PC to the mill, the 1 off PCB is
made, with milled outlines to the tracks.
Now having developed the program, Dwayne wants to distribute it.
My suggestion is to put the calculation engine that converts from the
original data to the milling machine code into the dongle. There is no
encryption/decryption involved. The dongle is part of the data path between
the original clear data, and the clear data fed to the mill machine. The
dongle does all the data manipulation, not the PC program.
By having the dongle do the data manipulation the PC program becomes little
more than a file server/transfer mechanism. The dongle HAS to be present for
the data manipulation to take place, and cannot be bypassed. The PC program
can be copied as many times as anyone likes, but when they disassemble it,
all they will find is a data path that goes from the input file to the
dongle. Then from the dongle to the output file. The output file could be a
disk file or it could be straight to the mill.
See also: www.piclist.com/techref/index.htm?key=shareware+software
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