What are Self-Decrypting Archives?
A Self-Decrypting Archive (SDA) is an executable containing a file that has been encrypted using a passphrase. A recipient of an SDA runs the executable and enters the passphrase to decrypt the file. SDAs are especially useful when the sender must send an encrypted file to a recipient who does not have PGP software installed. Creating an SDA requires the sender to know the recipient’s platform because SDA executables are platform-specific. An SDA can also be encrypted to an Additional Decryption Key (ADK) to allow corporate access to the encrypted data, according to policy, should the sender or recipient loose the passphrase required to decrypt the file.