if someone has an encrypted version of my ip. that is i encrypted my vhdl to produce vhldp file can he use this file to implement it on hardware or will he be only able to simulate my work to check it out.
If you encrypt it usually that is just to prevent them seeing the source code. They can usually integrate it into an FPGA. For simulation I have usually seen behavioural models of the IP supplied rather than simulating encrypted IP.