Electronic data communication system with encryption for electronic messages

• US 9,667,418 B2
• Filed: 10/23/2012
• Issued: 05/30/2017
• Est. Priority Date: 02/02/2006
• Status: Active Grant

• Current Assignee: Trend Micro Inc.
• Original Assignee: Trend Micro Inc.
• Inventors: Dancer, Andrew
• Primary Examiner(s): Kim, Tae
• Application Number:
  US13/658,572
• Publication Number:
  US 20130046986A1
• Time in Patent Office: 1,680 Days
• CPC Class Codes: H04L 2209/76 Proxy, i.e. using intermediary entity to perform cryptographic operations network architectures or network communication protocols using hop-by-hop encryption H04L63/0464
• CPC Class Codes: H04L 51/00 User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
• CPC Class Codes: H04L 63/045 wherein the sending and receiving network entities apply hybrid encryption, i.e. combination of symmetric and asymmetric encryption cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• CPC Class Codes: H04L 63/0471 applying encryption by an intermediary, e.g. receiving clear information at the intermediary and encrypting the received information at the intermediary before forwarding
• CPC Class Codes: H04L 63/126 the source of the received data
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates

Abstract

There is described an electronic data communication system in which encrypted mail messages for a recipient are sent in two parts: message data encrypted by a symmetric encryption algorithm using a session key and session key data encrypted by an asymmetric encryption algorithm using a public key associated with the recipient. If the recipient uses a webmail service to access the encrypted electronic mail message, the encrypted session key data is sent to a trusted third party server which has access to the private key of the user. The trusted third party server decrypts the encrypted session key using the private key of the user, and then sends the decrypted session key to a remote network device for decryption of the encrypted message.

Claims

1. A network server comprising:

a data store operable to store encrypted electronic messages for a recipient comprising i) encrypted message data corresponding to a message for the recipient encrypted by a symmetric encryption algorithm using a session key and ii) encrypted session key data corresponding to the session key encrypted by an asymmetric encryption algorithm using a public key of the recipient;

a network interface operable to receive data from and transmit data to remote network devices; and

a processor operable, following receipt of a request to access an encrypted electronic message, to extract said encrypted session key data from the requested electronic message and forward the extracted encrypted session key data but not the requested encrypted electronic message to a remote network device.

2. The network server according to claim 1, wherein the processor is operable to generate link data comprising the encrypted session key data and a network address for an encryption key server.

3. The network server according to claim 2, wherein the processor is operable to generate link data further comprising a redirect network address.

4. The network server according to claim 2, wherein the processor is operable to generate link data further comprising identification data for the recipient.

5. The network server according to claim 2, wherein the processor is operable to generate link data further comprising time data identifying a time period during which the encrypted electronic message was sent.

6. The network server according to claim 2, wherein the link data comprises a uniform resource locator.

7. The network server according to claim 6, wherein the processor is operable to incorporate the generated uniform resource locator in web page data.