Encryption and decryption using public TLS certificate. This is useful if you want someone to encrypt data to send to you, and you have access to the private key for a public website.

Decrypt.ps1

$certPassword = Read-Host "Certificate password"
$fullCertBytes = <certificate>
$fullCert = New-Object System.Security.Cryptography.X509Certificates.X509Certificate2
$fullCert.Import($fullCertBytes, $certPassword, 0)
$encrypted = [Convert]::FromBase64String((Read-Host "Encrypted password"))
[System.Text.Encoding]::UTF8.GetString(($fullCert.PrivateKey.Decrypt($encrypted, $true)))

Encrypt.ps1

$r = [System.Net.HttpWebRequest]::Create(<public website HTTPS url>)
$r.GetResponse().Dispose()
$cert = $r.ServicePoint.Certificate
$password = [System.Text.Encoding]::UTF8.GetBytes((Read-Host "Please enter the text to encrypt"))
$out = [Convert]::ToBase64String((New-Object System.Security.Cryptography.X509Certificates.X509Certificate2 $cert).PublicKey.Key.Encrypt($password, $true))