(Excel) 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.

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' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim crypt As Chilkat.Crypt2
Set crypt = Chilkat.NewCrypt2

' 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"


plainText = "To be encrypted."


encryptedText = crypt.EncryptStringENC(plainText)

Debug.Print encryptedText

' Now decrypt:

decryptedText = crypt.DecryptStringENC(encryptedText)

Debug.Print decryptedText