What does PowerShell remoting use to authenticate to another host in a domain environment?

PowerShell remoting is built upon the Windows Remote Management (WinRM) service. In a Windows Active Directory domain environment, WinRM defaults to using Kerberos for authentication. When a user on a domain-joined machine initiates a remote session to another, the client machine obtains a Kerberos service ticket from the domain controller's Key Distribution Center (KDC). This ticket is then presented to the target server to authenticate the user's identity securely without transmitting passwords or other secrets over the network. This is the standard mechanism for integrated Windows Authentication within a domain.

A. Two factor codes: This is a method for multi-factor authentication (MFA), not the underlying authentication protocol used by default for PowerShell remoting.

B. Unique application passwords: These are typically used as an alternative to user passwords for applications that do not support modern authentication methods, not for interactive remoting.

C. PreShared keys: These are symmetric keys used in protocols like IPsec or WPA for authentication and are not the default mechanism for PowerShell remoting in a domain.

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1. Microsoft Corporation. (2023

September 15). About Remote Requirements. Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/aboutremoterequirements.

Under the "User permissions" section

it states

"By default

PowerShell remoting uses Kerberos to authenticate users and to encrypt data."

2. Microsoft Corporation. (2023

September 21). Installation and configuration for Windows Remote Management. Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/windows/win32/winrm/installation-and-configuration-for-windows-remote-management.

In the "Authentication for remote connections" section

the documentation specifies

"In a domain

WinRM uses Kerberos for authentication. If the client is in a domain

but the remote computer is not

then you must add the remote computer to the client's list of trusted hosts."

3. Massachusetts Institute of Technology (MIT). (2011). 6.857 Computer and Network Security

Lecture 15: Kerberos. MIT OpenCourseWare. Retrieved from https://ocw.mit.edu/courses/6-857-computer-and-network-security-fall-2011/resources/mit6857f11lec15/.

This resource provides the foundational principles of the Kerberos protocol (Section: "Kerberos v5")

which is the technology leveraged by services like WinRM/PowerShell for authentication in a trusted domain environment.