![]() ![]() The security handler sets up the encryption key and writes extra security-related information into the PDF file’s encryption dictionary.Ī user attempts to change a document’s security settings. The security handler determines whether a user is authorized to open the file and sets up the decryption key that is used to decrypt the PDF file.Ī document is saved. Security handlers are used in the following situations:Ī document is opened. ![]() Maintaining the encryption dictionary of the PDF file containing the document Setting up a file’s encryption and decryption keys Security handlers are responsible for performing the following tasks: You can use the Acrobat core API’s built-in security handler or write your own security handlers to perform user authorization (for example, by the presence of a specific hardware key or file, or by reading a magnetic card reader). (See the Acrobat and PDF Library API Reference.)Ī security handler supports two passwords:Ī user password that enables a user to open and read a protected document with whatever permissions the owner choseĪn owner password that allows a document’s owner to also change the permissions granted to users Acrobat has these built-in security handlers: password, Adobe and public key security handler. Security handlers may instead choose to ignore these methods and use their own encryption algorithms.Īpplication logic that performs user authorization and sets permissions is known as a security handler. Security handlers may use these methods to encrypt data they want to put into the PDF file’s encryption dictionary and decrypt data when it is read from the dictionary. (See the Acrobat and PDF Library API Reference.) These methods are CosEncryptData and CosDecryptData. The core API provides two Cos layer methods to encrypt and decrypt data using the RC4 algorithm. If the security handler does not encrypt the values it places into the encryption dictionary, the values are in plain text. A plugin may not substitute another encryption scheme for RC4.Ī plugin that implements a security handler is responsible for encrypting the values it places into the encryption dictionary, and it may use any encryption scheme. All objects, except for the encryption dictionary (which contains the security handler’s private data), are encrypted using the RC4 algorithm Adobe licenses from RSA Data Security, Inc. This level of encryption improves performance because objects can be individually decrypted as needed rather than decrypting an entire file. The Acrobat core API uses RC4 (a proprietary algorithm provided by RSA Data Security, Inc.) to encrypt document data, and a standard (proprietary) method to encrypt, decrypt, and verify user passwords to determine whether or not a user is authorized to open a document.Įach stream or string object in a PDF file is individually encrypted. Encryption is controlled by an encryption dictionary in the PDF file. ![]()
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