Irreversible encrypted password in HPE LoadRunner

I have been running some performance test on one of my websites and I have been trying to encrypt my password for safety reasons. Every method I have tried is easily reversible if someone has access to my scripts. Does anyone know how to do this properly? LoadRunner documentation is quite poor. I have tried

Using parameters: (actual password can be seen in paramaters)

"Name=Username", "Value={Username}", ENDITEM, 
"Name=Password", "Value={Password}", ENDITEM, 

Using masked strings, can be also reversible.

"Name=Username", lr_unmask("5c5c433589e471556dd55bdac0336170f7c36ea3b32869fec2ee1ffa15"), ENDITEM, 

Any help would be greatly appreciated, thanks