System and Method for Cipher E-Mail Protection
The preferred embodiments of the present invention disclose a security transformation system which includes an e-mail client, a cipher proxy, a dictionary database and an Internet e-mail system. The system is capable of generating and receiving messages and performing a cipher substitution and encryption of key fields of messages when they are stored at a user's Internet e-mail system. When the messages are received or accessed the system permits deciphering and decrypting the message using a reverse security transformation The preferred embodiments of the method of the present invention comprises steps of generating and receiving messages at an Internet e-mail system, performing a security transformation on said messages, encrypting said messages, updating a cipher dictionary at a cipher proxy, and decoding and decrypting the messages when accessed by a user.
1 . A cipher e-mail protection system, comprising:
an e-mail store at a first location;
an Internet e-mail system;
a cipher-proxy device for transmitting messages from said e-mail store to said Internet e-mail system;
a dictionary database for ciphering and reverse ciphering attributes of messages between said e-mail store and said Internet e-mail system; and
an encryption and decryption mechanism for encrypting and decrypting attributes of said messages.
2 . A method for securing messages, comprising the steps of:
generating a message;
performing a security transformation in said message in one or more fields;
transmitting said transformed message to an Internet e-mail system; and
storing said transformed message at the Internet e-mail system.
3 . The method of claim 2 , wherein the security transformation for a given field is a term substitution cipher,
4 . The method of claim 2 , wherein the security transformation for a given field is asymmetric encryption.
5 . The method of claim 2 , wherein the security transformation for a given field is symmetric encryption.
6 . A method of generating and accessing transformed messages, comprising the steps of:
generating a message;
performing a security transformation in said message in one or more fields;
transmitting the transformed message to an Internet e-mail system;
storing said transformed message at the Internet e-mail system; and
accessing said message and performing a reverse security transformation on said message.
7 . The method of claim 6 , wherein the security transformation for a given field is a term substitution cipher.
8 . The method of claim 6 , wherein the security transformation for a given field is asymmetric encryption.
9 . The method of claim 6 , wherein the security transformation for a given field is symmetric encryption.
10 . The method of claim 7 , comprising:
creating a cipher index;
searching for said message using said cipher index;
retrieving said transformed message;
decoding said transformed message using said cipher index; and
viewing said message with an e-mail client.
11 . A method for performing a security transformation on a message, comprising the steps of:
generating a message;
performing a cipher substitution of attributes of said message;
encrypting attributes of said message;
transmitting said transformed and encrypted message from an e-mail store to an Internet e-mail system; and
storing said transformed and encrypted message at the Internet e-mail system.
12 . A method of generating and accessing ciphered messages, comprising the steps of:
generating a message at first location;
performing a cipher substitution of terms in a message;
creating a cipher index;
encrypting said index;
transmitting the ciphered and encrypted message to the Internet e-mail system;
storing said ciphered message at the Internet e-mail system;
searching said message using said cipher index;
retrieving said ciphered and encrypted message;
decoding said ciphered message using said cipher index;
decrypting said index;
decrypting attributes of said message; and
viewing said message with an e-mail client;
13 . The method of claim 12 , wherein the message is identified by searching said message using said cipher index.
14 . A method of generating and accessing ciphered messages, comprising the steps of:
replacing required terms in an email message with corresponding terms from a dictionary for the folder or mailbox;
if a new term is encountered while replacing, creating a new mapping in the dictionary, and replacing the new word with the new cipher term;
identifying all terms used by the email message;
creating a subset of the dictionary for the terms of the message;
encrypting the subset dictionary using a symmetric encryption algorithm;
attaching the encrypted subset dictionary to the email message in an extended attributes field;
using PKI technology to encrypt the symmetric key using a set of public keys for one or more users as required;
placing the encrypted symmetric key packages in an extended attributes field;
placing an encrypted term index for the message in an extended attribute field;
transmitting the coded email to the Internet e-mail system account where it is stored;
transmitting the coded email to the organizational archive where a copy is stored;
decrypting the encrypted term index; and
integrating the term index as references to this email into the corporate index
15 . The method of claim 14 , wherein a variety of redundant entries are provided in the dictionary for at least frequently-used terms to defeat potential word-frequency attacks.
16 . The method of claim 1 , wherein a variety of redundant entries are provided in the term index for at least frequently-used terms to defeat potential word-frequency attacks.