Verify Computer Name against Active Directory in SCCM task sequence

Recently, I have been asked by one of my customers, for computer name checks against Active Directory before setting it in SCCM task sequence for new computer deployment.
Searching the web didn't came up with any results, and since the request sounded really reasonable to me, I decided to take the challenge.

My solution had to be secure. meaning, password cannot be written in clear text or any other non-secure method in any way.

After a lot of research I came up with the following steps to complete this request:

1.  Enable PowerShell in boot images.
2. Create a package that copy's Active Directory module files to the boot image, and run it in task sequence.
3. Create a PowerShell script that do the following:
• Interact with task sequence.
• load PowerShell form for prompting computer name selection.
• Import Active Directory module, securely connect to Active Directory and check the name against Active Directory.
• Set computer name as OSDComputername TS variable (assuming that the name not exists).