Secure electronic mail system

Details Secure electronic mail system Secure electronic mail system

1999-01-28

2002-12-24

Hayes, Gail (Department: 2131)

Electrical computers and digital processing systems: support

Multiple computer communication using cryptography

Protection at a particular protocol layer

C713S184000, C713S176000, C380S028000

Reexamination Certificate

active

06499108

ABSTRACT:

REFERENCE TO MICROFICHE APPENDIX
This application is not referenced in any microfiche appendix.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to an apparatus and method for a secure electronic mail communication system. More particularly, the invention is directed for use in communicating over networks where secure information exchange is required. The invention has utility in applications such as person-to-person communication over network systems, communications over the Internet, interbusiness network communications where security is required, and the like.
2. Prior Art
The use of keys for secure communications is well known. Secure communication systems, as well as key systems, are shown in U.S. Pat. No. 4,182,933, issued to Rosenblum on Jan. 8, 1980, entitled “Secure Communication System With Remote Key Setting”; U.S. Pat. No. 4,310,720, issued to Check, Jr. on Jan. 12, 1982; entitled “Computer Accessing System”; U.S. Pat. No. 4,578,531, issued to Everhart et al., on Mar. 25, 1986, entitled “Encryption System Key Distribution Method and Apparatus”; U.S. Pat. No. 4,965,804, issued to Trbovich et al. on Oct. 23, 1990, entitled “Key Management for Encrypted Packet-Based Networks”; U.S. Pat. No. 5,204,961, issued to Barlow on Apr. 20, 1993, entitled “Computer Network Operating With Multi-Level Hierarchial Security With Selectable Common Trust Realms and Corresponding Security Protocols”; and U.S. Pat. No. 5,416,842, issued to Aziz on May 16, 1995 entitled “Method and Apparatus For Key-Management Scheme For Use With Internet Protocols At Site Firewalls”.
U.S. Pat. No. 4,182,933, issued to Rosenblum on Jan. 8, 1980, discusses a “Secure Communication System With Remote Key Setting”. The Rosenblum '933 patent describes a system wherein a first subscriber communicates with a key distribution center to get an updated key to initiate secure communications with a second subscriber. An overview of the system shows that the user dials a telephone number into the first subscribing unit. The first subscribing unit then places the telephone number into temporary memory storage. The first subscriber then retrieves its initial caller variable from memory and places it into a key generator. The first subscriber then retrieves the number of the key distribution center (KDC) from its memory and dials the number. Once a connection has been established the first subscriber sends its caller ID as well as the caller ID of the telephone number being called to the KDC. This information is not yet transmitted in a secure manner.
Once the KDC has received the information from the first subscriber, the KDC looks up the caller variable for both the first subscriber and for the telephone number being called. The KDC then generates a new caller variable for the first telephone number. The KDC then transmits the caller variable for the number being called, a new caller variable for the first subscriber, using a secure transmission controlled by the initial caller variable. If this transmission is successful, then the KDC will replace the old caller variable in its table format with a new caller variable and break the connection.
Once the first subscriber has received and deciphered the caller variable for the number to be called and its new key caller variable, it will replace the old and used initial caller variable key with the new caller variable key. The first subscriber will then send the key for the number to be called to the key generator, retrieve the telephone number to be called, and dial the telephone number. The first subscriber will then transmit any information input by the user to the second subscriber using the second subscriber key. The second subscriber will receive information that has been encoded with the second subscriber key and will decode the information and transfer it on to the second user. In an alternative embodiment, after the phone call between the first subscriber and second subscriber, the second subscriber will call and get a new key from the KDC. In this alternative embodiment, both the key for the first subscriber and for the second subscriber will be changed out on every telephone call.
U.S. Pat. No. 4,310,720, issued to Check, Jr. on Jan. 12, 1982 discloses a “Computer Accessing System”. The specification discloses a method for communicating between an access unit and a computer. The user enters his password into an input device which is connected to an access unit. The access unit generates a pseudo random access key from the password that is entered. The access unit then sends the access unit number and the generated access key to the computer controller for access to the computer system. The computer controller receives the access unit number and access key. The computer controller then verifies the access unit number. If the access unit number is properly verified, the computer controller will then compare the access code to the expected access code listed in a table in the computer's memory. This expected access code is generated using a congruent pseudo-random decoding algorthym. If the access key code and the expected code match, then the computer controller will establish a link between the access unit and the computer.
The access unit and the computer will talk through an encoded communication system. Both the access unit and the computer will use a randomly generated encryption key for encoding and decoding the communication. This key is independently generated by both the access unit and the computer and is not transmitted over the access unit to computer link. After the termination of the call between the access unit and the computer, the computer will generate and store the next access key number for that particular access unit.
U.S. Pat. No. 4,578,531 issued to Everhart et al. on Mar. 25, 1986 discloses an “Encryption System Key Distribution Method and Apparatus”. This system allows the secure method for communication between a terminal “A” and terminal “B” by using a remote key distribution center. An initial signal is sent from terminal “A” to terminal “B” to initiate the process of generating a secure communication line. Terminal “A” then generates a new call set up key in preparation for communication with the key distribution center, and a partial session key which will be transmitted through the key distribution center to terminal “B”. Terminal “A” then updates its verification information in preparation for communication with the key distribution center. Terminal “A” then initiates the connection with the key distribution center to which it sends its terminal address and the terminal “B” address and an encrypted message including the two generated keys and the verification information. At this point, terminal “A” will wait for the processing by the key distribution center.
The key distribution center will read the address information from the signal sent from terminal “A” and use this to access a de-cryption key previously sent in communication with terminal “A”. The message from terminal “A” will then be de-crypted and the verification information will be updated. The key distribution center will then generate a bidirectional asymmetric encryption/de-cryption key pair. The first part of this key pair will be sent to terminal “A”, and the second part of the key pair will be sent to terminal “B”. A similar communication will happen with terminal “B”.
The message to terminal “A” will consist of a subsequent call key for the next communication with a KDC, a partial session key which it received from terminal “B”, verification information, and two other variables “Y” and “Q”. These five pieces of information will be encrypted using the call set up key for the present communication with terminal “A” and the information will be transmitted to terminal “A”. A similar encrypted message will also be sent to terminal “B” from the KDC.
Terminal “A” will de-crypt the message from the KDC and verify that the information is correct. Terminal “A” will then store the new communication key for the next communicat

Affiliated with

Also associated with

Rating

Secure electronic mail system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Secure electronic mail system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Secure electronic mail system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2990509