Encrypt Method
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EnvelopedData.Encrypt method

[CAPICOM is a 32-bit only component that is available for use in the following operating systems: Windows Server 2008, Windows Vista, and Windows XP. Instead, use the EnvelopedCms Class in the System.Security.Cryptography.Pkcs namespace.]

The Encrypt method generates a session key, uses that key to encrypt the contents, envelops the encrypted content for each recipient by encrypting the session key with each recipient's public key, and then returns the BLOB that contains the encrypted contents and the encrypted session keys as an encoded string.


EnvelopedData.Encrypt( _
  [ ByVal EncodingType ] _


EncodingType [in, optional]

A value of the CAPICOM_ENCODING_TYPE enumeration that indicates the encoding type used to encode the enveloped data. The default encoding value is CAPICOM_ENCODE_BASE64. This parameter can be one of the following values.


This encoding type is used only when the input data has an unknown encoding type. If this value is used to specify the output's encoding type, CAPICOM_ENCODE_BASE64 will be used instead. Introduced in CAPICOM 2.0.


Data is saved as a base64-encoded string.


Data is saved as a pure binary sequence.


Return value

This method returns a BLOB that contains the enveloped data in an encoded string.


The returned BLOB contains the encrypted content and an encrypted session key for each intended recipient. These session keys are encrypted using the public key of each recipient. The encrypted session keys can be decrypted only with a recipient's private key.

If the Recipients property does not contain any information, this method searches the current user's AddressBook certificate store for potential recipients. If more than one potential recipient is found, the user is prompted to select a recipient from a selection dialog box.


End of client support

Windows Vista

End of server support

Windows Server 2008


CAPICOM 2.0 or later on Windows Server 2003 and Windows XP



See also

Cryptography Objects



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