If you enable encryption for a share or the entire server, clients are not given access if they send unencrypted requests. If you disabled SMB Encryption on a server, however, you can subsequently enable encryption for individual shares. If SMB Encryption is configured for a server, you have no way to make adjustments at the share level. SMB Encryption can thus be defined per server for all shares or for individual shares. In exceptional cases, access can be unencrypted: > Set-SmbServerConfiguration -RejectUnencryptedAccess
> New-SmbShare -Name -Path -EncryptData 1 SMB Encryption can be controlled using these PowerShell cmdlets: > Set-SmbServerConfiguration -EncryptData The two functions can be used in parallel, because it is the only way to make sure the client and server cannot be compromised and to avoid data sniffing. In addition to SMB Encryption is SMB Signing.
If the client and server both support AES-128-GCM, this new technology is used however, if you have clients running Windows 8.1 or Windows Server 2012 R2 or older, Windows Server 2016 and Windows 10 will use AES-128-CCM communications instead. Clients and servers negotiate which technology to use during the connection establishment process. Windows 10 and Windows Server 2016 both also offer AES-128-CCM, however.
Microsoft states a possible performance increase of 100 percent when copying large files over the network. Both of these new features are capable of communicating via SMB 3.1.1. According to Microsoft, this encoding can cope better with the latest Intel and AMD processors and can accelerate access via SMB, especially between servers (e.g., where Storage Spaces Direct or the new Storage Replica in Windows Server 2016 is used). SMB 3.1.1 uses AES-128-GCM for encryption. That can be problematic, especially for systems that connect different data centers and the servers installed therein. Third-party products that do not use Secure Negotiate are blocked by Windows Server 2016, unless they support pre-authentication integrity. In connections with older versions of SMB, you cannot bypass Secure Negotiate, which stabilizes the connection to older systems. In SMB 3.1.1, Secure Negotiate is replaced by pre-authentication integrity.
Microsoft designates this new feature "pre-authentication integrity." The authentication data is encrypted with SHA-512.īecause the older Secure Negotiate function is rarely used and has caused some problems – especially with third-party software – you can now disable this feature, which can improve communication performance, especially if you are not using the function anyway. In SMB 3.1.1, the cipher is exchanged during the connection establishment process, the aim being to ensure that security is in place even before the client and server have mutually authenticated.
SMB 3.0 in Windows 7 and Windows Server 2012 already did its best to restrict access to data transmitted by attackers. The new version of the SMB protocol can prevent man-in-the-middle attacks by extending SMB encryption.