$Path = "$env:temp/secret.txt"$Secret = 'Hello World!'$Passphrase = 'Some secret key' $key = [Byte[]]($Passphrase.PadRight(24).Substring(0,24).ToCharArray()) $Secret | ConvertTo-SecureString -AsPlainText -Force | ConvertFrom-SecureString -Key $key | Out-File -FilePath $Path notepad $Path

$Passphrase = Read-Host 'Enter the secret pass phrase' $Path = "$env:temp/secret.txt" $key = [Byte[]]($Passphrase.PadRight(24).Substring(0,24).ToCharArray()) try{ $decryptedTextSecureString = Get-Content -Path $Path -Raw | ConvertTo-SecureString -Key $key -ErrorAction Stop  $cred = New-Object -TypeName System.Management.Automation.PSCredential('dummy', $decryptedTextSecureString) $decryptedText = $cred.GetNetworkCredential().Password}catch{ $decryptedText = '(wrong key)'}"The decrypted secret text: $decryptedText"