Secure E-Mail Messaging System

• US 20100017598A1
• Filed: 07/21/2008
• Published: 01/21/2010
• Est. Priority Date: 07/21/2008
• Status: Active Grant

• Current Assignee: Forcepoint Federal Holdings LLC (Forcepoint LLC)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Visaria, Jay J., Oberai, Tina A., Farley, Thomas D., Pippins, Jerry L. JR., Rodriguez, Ricardo J., Stahl, Noah Z.
• Granted Patent: US 8,359,357 B2
• Time in Patent Office: Days
• US Class Current: 713/156
• CPC Class Codes: H04L 51/48 Message addressing, e.g. address format or anonymous messages, aliases

Abstract

According to one embodiment, a secure e-mail messaging system includes an e-mail relay server coupled to a secure client configured on a secure domain and an external client configured on an external domain. The e-mail relay server has a memory for storage of an actual address of the secure client, a first certificate associated with the actual address, an alias address associated with the actual address, and a second certificate associated with the alias address. The e-mail relay server receives an e-mail message that includes the alias address from the external client and decrypts the e-mail message according to the second certificate. The e-mail messaging server then replaces the alias address with the actual address to form a modified e-mail message, encrypts the modified e-mail message according to the first certificate, and transmits the modified e-mail message to the secure client.

Claims

1. A secure e-mail messaging system comprising:

an e-mail relay server coupled to a secure client configured on a secure domain and an external client configured on an external domain, the e-mail relay server having a memory for storage of an actual address of the secure client, a first certificate associated with the actual address, an alias address associated with the actual address, and a second certificate associated with the alias address, the e-mail relay server operable to;

receive an e-mail message comprising the alias address from the external client, the e-mail message being encrypted according to the second certificate;

decrypt the e-mail message according to the second certificate;

replace the alias address with the actual address to form a modified e-mail message;

encrypt the modified e-mail message according to the first certificate; and

transmit the modified e-mail message to the secure client.

2. The secure e-mail messaging system of claim 1, wherein the e-mail relay server is further operable to:

receive another e-mail message comprising the actual address from the secure client, the e-mail message being encrypted according to the first certificate;

encrypt the another e-mail message according to the first certificate;

replace the actual address with the alias address to form another modified e-mail message;

encrypt the another modified e-mail message according to the second certificate; and

transmit the another modified e-mail message to the external client.

3. The secure e-mail messaging system of claim 1, wherein the e-mail relay server is operable to decrypt the e-mail message according to the second certificate by decrypting the e-mail message according to a private key of the alias address and verify an external address of the external client according to a public key of the external client.

4. The secure e-mail messaging system of claim 1, wherein the first domain comprises a secure network having a security level that differs from the security level of the second domain.

5. The secure e-mail messaging system of claim 1, wherein the first certificate is isolated from the second domain and the second certificate is isolated from the first domain.

6. The secure e-mail messaging system of claim 1, further comprising a guard node coupled to the e-mail relay server, the guard node operable to verify the e-mail message according to a plurality of rules.

7. The secure e-mail messaging system of claim 6, wherein the guard node is operable to verify the first e-mail message by searching the body portion for instances of one of a plurality of key phrases or one of a plurality of keywords and if found, restrict the e-mail relay server from transmitting the modified e-mail message.

8. The secure e-mail messaging system of claim 1, wherein e-mail relay server is coupled to the secure client through a domain gateway, the domain gateway operable to compartment information transmitted from the secure domain to the external domain.

9. A secure e-mail messaging method comprising:

receiving an e-mail message comprising an alias address from an external client configured on an external domain, the alias address associated with an actual address of a secure client configured on a secure network, the e-mail message being encrypted according to a second certificate associated with the alias address;

decrypting the e-mail message according to the second certificate;

replacing the alias address with the actual address to form a modified e-mail message;

encrypting the modified e-mail message according to a first certificate associated with the actual address; and

transmitting the modified e-mail message to the secure client.

10. The secure e-mail messaging method of claim 9, further comprising receiving another e-mail message comprising the actual address from the secure client, the e-mail message being encrypted according to the first certificate, encrypting the another e-mail message according to the first certificate, replacing the actual address with the alias address to form another modified e-mail message, encrypting the another modified e-mail message according to the second certificate, and transmitting the another modified e-mail message to the external client.

11. The secure e-mail messaging method of claim 9, wherein decrypting the e-mail message according to the second certificate further comprises decrypting the e-mail message according to a private key of the alias address and verifying an external address of the external client according to a public key of the external client.

12. The secure e-mail messaging method of claim 9, wherein receiving the e-mail message from the external client configured on the external domain comprises receiving the e-mail message from the external client configured on the external domain having a security level that differs from the security level of the secure domain.

13. The secure e-mail messaging method of claim 9, wherein encrypting the modified e-mail message according to the first certificate comprises encrypting the modified e-mail message according to the first certificate that is isolated from the external domain.

14. The secure e-mail messaging method of claim 9, further comprising verifying the e-mail message according to a plurality of rules.

15. The secure e-mail messaging method of claim 14, wherein verifying the e-mail message according to a plurality of rules comprises searching the body portion for instances of one of a plurality of key phrases or one of a plurality of keywords and if found, restricting the e-mail relay server from transmitting the modified e-mail message.

16. The secure e-mail messaging method of claim 9, further comprising compartmenting information that is transmitted from the secure domain to the external domain.

17. Code embodied on a computer-readable medium, when executed on a computer processor, operable to perform at least the following:

receive an e-mail message comprising an alias address from an external client configured on an external domain, the alias address associated with an actual address of a secure client configured on a secure network, the e-mail message being encrypted according to a second certificate associated with the alias address;

decrypt the e-mail message according to the second certificate;

replace the alias address with the actual address to form a modified e-mail message;

encrypt the modified e-mail message according to a first certificate associated with the actual address; and

transmit the modified e-mail message to the secure client.

18. The code of claim 17, further operable to receive another e-mail message comprising the actual address from the secure client, the e-mail message being encrypted according to the first certificate, encrypt the another e-mail message according to the first certificate, replace the actual address with the alias address to form another modified e-mail message, encrypt the another modified e-mail message according to the second certificate, and transmit the another modified e-mail message to the external client.

19. The code of claim 17, further operable to decrypt the e-mail message according to the second certificate by decrypting the e-mail message according to a private key of the alias address and verifying an external address of the external client according to a public key of the external client.

20. The code of claim 17, further operable to receive the e-mail message from the external client configured on the external domain that has a security level that differs from the security level of the secure domain.

21. The code of claim 17, further operable to encrypt the modified e-mail message according to the first certificate that is isolated from the external domain.

22. The code of claim 17, further operable to verify the e-mail message according to a plurality of rules.

23. The code of claim 22, further operable to verify the e-mail message by searching the body portion for instances of one of a plurality of key phrases or one of a plurality of keywords and if found, restricting the e-mail relay server from transmitting the modified e-mail message.

24. The code of claim 17, further operable to compartment information that is transmitted from the secure domain to the external domain.