Encryption - RSA Encrypt and Decrypt Strings

RSA Encrypt and Decrypt Strings
Dim rsa As New Chilkat.Rsa()
Dim success As Boolean
success = rsa.UnlockComponent("Anything for 30-day trial")
If (success <> true) Then
MsgBox("RSA component unlock failed")
Exit Sub
End If

' This example also generates the public and private
' keys to be used in the RSA encryption.
' Normally, you would generate a key pair once,
' and distribute the public key to your partner.
' Anything encrypted with the public key can be
' decrypted with the private key. The reverse is
' also true: anything encrypted using the private
' key can be decrypted using the public key.
' Generate a 1024-bit key. Chilkat RSA supports
' key sizes ranging from 512 bits to 16384 bits.

success = rsa.GenerateKey(1024)

If (success <> true) Then
MsgBox(rsa.LastErrorText)
Exit Sub
End If

' Keys are exported in XML format:
Dim publicKey As String
publicKey = rsa.ExportPublicKey()
Dim privateKey As String
privateKey = rsa.ExportPrivateKey()


Dim plainText As String
plainText = "Encrypting and decrypting should be easy!"

' Start with a new RSA object to demonstrate that all we' need are the keys previously exported:
Dim rsaEncryptor As New Chilkat.Rsa()

' Encrypted output is always binary. In this case, we want
' to encode the encrypted bytes in a printable string.
' Our choices are "hex", "base64", "url", "quoted-printable".

rsaEncryptor.EncodingMode = "hex"

' We'll encrypt with the public key and decrypt with the private
' key. It's also possible to do the reverse.
rsaEncryptor.ImportPublicKey(publicKey)
Dim usePrivateKey As Boolean
usePrivateKey = false
Dim encryptedStr As String
encryptedStr = rsaEncryptor.EncryptStringENC(plainText,usePrivateKey)
TextBox1.Text = TextBox1.Text & encryptedStr & vbCrLf
TextBox1.Refresh()

' Now decrypt:
Dim rsaDecryptor As New Chilkat.Rsa()
rsaDecryptor.EncodingMode = "hex"
rsaDecryptor.ImportPrivateKey(privateKey)
usePrivateKey = true
Dim decryptedStr As String
decryptedStr = rsaDecryptor.DecryptStringENC(encryptedStr,usePrivateKey)
TextBox1.Text = TextBox1.Text & decryptedStr & vbCrLf
TextBox1.Refresh()



http://www.example-code.com/vbdotnet/rsa_encryptStrings.asp