As an employer, I would never employ someone who said this (the emphasis in bold is mine):
The technical lead asked me to show some sample outputs of my work but I can't show my sample output because the outputs I've done is ONLY for use inside of my past company and its very confidential.
Note that in my past company. Flash Drives are prohibited and uploading is monitored. That's is why I cant really copy my work outside the company.
The real reason you can't show your work outside your company is because you're not allowed to. That's it. It's as simple as that.
It doesn't matter what the security protocols are, or even if the security protocols are non-existent. If you're not allowed to, you're not allowed to. And even hinting that you might be desperate enough to breach the confidentiality of your previous employer would only indicate to me that you might be willing to breach the confidentiality of my own company if I hired you.
As to the other answers, they're absolutely correct. You need to work on your own side projects or open source projects.