Digital Envelope

A digital envelope enables the protection of data with the speed of secret-key encryption along with the ease and enhanced security of public-key encryption. When using a digital envelope, there isn’t a need to communicate with the plaintext required by a secret key to decrypt the data. A digital envelope may be created in the following ways: - using a secret key algorithm such as Rijndael to encrypt plaintext or compressed plaintext. - using a Public-key algorithm to encrypt a secret key with a public key. A digital envelope may be decrypted in the following ways: - using a recipient’s private key to decrypt the secret key. - using a secret key to decrypt encrypted data. PGP (Pretty Good Protection) is a popular encryption algorithm that can be classified as a digital envelope. It generally uses a deflate compression algorithm to compress plaintext. PGP then uses an algorithm such as IDEA, CAST5 or Triple DES to encrypt plaintext. It uses an algorithm such as RSA to encrypt the secret key.