PBES2 Password-Based Encryption (PBE)

Demonstrates how to implement password-based encryption according to the PKCS #5 v2.0: Password-Based Cryptography Standard (published by RSA Laboratories). This example uses PBES2, which ise based on the PBKDF2 function and an underlying block cipher such as RC2, DES, etc.

Download: Chilkat .NET Assemblies

Dim crypt As New Chilkat.Crypt2()

Dim success As Boolean
success = crypt.UnlockComponent("Anything for 30-day trial")
If (success <> true) Then
    MsgBox(crypt.LastErrorText)
    Exit Sub
End If


'  Set properties for PBES2 encryption:

crypt.CryptAlgorithm = "pbes2"
crypt.PbesPassword = "mySecretPassword"

'  Set the underlying PBE algorithm (and key length):
crypt.PbesAlgorithm = "rc2"
crypt.KeyLength = 128
'  Only required for the RC2 algorithm:
crypt.Rc2EffectiveKeyLength = 128

'  By definition, the block encryption algorithm (RC2 or whichever
'  was selected) will run in CBC mode.  Therefore, we need
'  an IV.  The IV is equal in length to the block size of the
'  algorithm.  RC2 has a block size of 8 bytes (regardless of
'  key length), so set the IV to some value that is 8 bytes
'  in length:
crypt.SetEncodedIV("0000000000000000","hex")

'  Give it some salt:
crypt.SetEncodedSalt("0102030405060708","hex")

'  A higher iteration count makes the algorithm more
'  computationally expensive and therefore exhaustive
'  searches (for breaking the encryption) is more difficult:
crypt.IterationCount = 1024

'  A hash algorithm needs to be set for PBES2:
crypt.HashAlgorithm = "sha1"

'  Indicate that the encrypted bytes should be returned
'  as a hex string:
crypt.EncodingMode = "hex"

Dim plainText As String
plainText = "To be encrypted."

Dim encryptedText As String
encryptedText = crypt.EncryptStringENC(plainText)

TextBox1.Text = TextBox1.Text & encryptedText & vbCrLf

'  Now decrypt:
Dim decryptedText As String
decryptedText = crypt.DecryptStringENC(encryptedText)

TextBox1.Text = TextBox1.Text & decryptedText & vbCrLf