# US 2008/0187140 A1 · Method and System of Securely Transmitting Electronic Mail > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0187140 A1 - Document ID: US20080187140A1 - Status: Published application - Kind: A1 - Application number: 11/946,171 - Filed: 2007-11-28 - Published: 2008-08-07 - Earliest claimed: 2007-02-07 - Assignees: Comodo CA Limited - Inventors: Shane McGillian; Melih Abdulhayoglu - Web page: https://patentgrep.com/patent/US20080187140A1 ## CPC - H04L 63/062: {for key distribution, e.g. centrally by trusted party (cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819)} - 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 - H04L 63/0442: {wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption (cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method of encrypting email where a email is intercepted from an email sender, a public and private key pair is generated, and the private key is used to encrypt the email. A secure connection is then established with a server and the private key is sent to the server. The email is sent to the recipients who then connects to the server. The server performs authentication on the recipients. The recipients request the private key from the server which is returned by the server. The email is then decrypted using the returned private key. ## Claims ### Claim 1 A method of encrypting email comprising the steps of intercepting at least one email from an email sender generating at least one public and private key pair, encrypting at least one intercepted email; creating at least one encrypted connection to a server; sending at least one private key to the server over at least one encrypted connection; sending at least one encrypted email to at least one recipient having at least one encrypted connection between the server and at least one recipient having the server authenticate at least one recipient having at least one recipient request the at least one private key from the server having the server return at least one private key; and decrypting the email using at least one private key returned by the server. ### Claim 2 (depends on 1) A method of encrypting email according to claim 1, where at least one public key is stored in at least one public key certificate that is self-signed using a corresponding private key. ### Claim 3 (depends on 2) A method of encrypting email according to claim 2, where the subject of at least one public key certificate is at least one of the recipient's email address. ### Claim 4 (depends on 1) A method of encrypting email according to claim 1, where the server is a secure server hosted by a trusted third party. ### Claim 5 (depends on 1) A method of encrypting email according to claim 1, where the server authenticates at least one recipient by examining at lest one digital certificate associated with the recipient ### Claim 6 (depends on 5) A method of encrypting email according to claim 5, where the server checks that at least digital certificate associated with the recipient has been signed by a known trusted root. ### Claim 7 (depends on 5) A method of encrypting email according to claim 5, where the server compares at least one email address associated with a digital certificate that is associated with at least one recipient to at least one email address that is the same address as the email intercepted from the email sender. ### Claim 8 (depends on 1) A method of encrypting email according to claim 1, where the server authenticates at least one recipient by proving the recipient has ownership of the private key corresponding to the recipients supplied public key. ### Claim 9 (depends on 8) A method of encrypting email according to claim 8 where the recipient's ownership of the private key is proved by requesting data from a successful private key operation. ### Claim 10 (depends on 1) A method of encrypting email according to claim 1, where the server is provided with at least one email certificate associated with at least one recipient. ### Claim 11 (depends on 10) A method of encrypting email according to claim 10, where the server is provided with at least one email certificate when the server authenticates at least one recipient. ### Claim 12 (depends on 10) A method of encrypting email according to claim 10, where the server sends at least one email certificate provided to the email sender. ### Claim 13 (depends on 12) A method of encrypting email according to claim 12, where the server sends the at least one email certificate by receiving at least one signed email certificate that is signed by at least one recipient's private key. ### Claim 14 (depends on 13) A method of encrypting email according to claim 13 where the email certificate sent to the email sender is part of an email generated by the server sending the email. ### Claim 15 (depends on 13) A method of encrypting email according to claim 13 where the email certificate is intercepted and the email certificate is extracted and installed on the email sender's computer. ### Claim 16 (depends on 1) A method of encrypting email according to claim 1 where at least one encrypted email is sent with a second non-encrypted email. ### Claim 17 (depends on 16) A method according to claim 16, where the at least one encrypted email is embedded in the second non-encrypted email. ### Claim 18 (depends on 16) A method according to claim 16, where at least one identifier of the email sender is sent to at least one recipient. ### Claim 19 (depends on 18) A method according to claim 18, where at least one identifier is an image file. ### Claim 20 A method of encrypting email comprising the steps of intercepting at least one email from an email sender generating at least one public and private key pair, encrypting at least one intercepted email; creating at least one encrypted connection to a server; sending at least one private key to the server over the at least one encrypted connection; sending at least one encrypted email having at least one computer receive at least one encrypted email sending notification of at least one encrypted email to at least one recipient having at least one recipient establish a secure connection to at least one computer that received an encrypted email decrypting the received encrypted email using at least one of the generated private keys displaying the contents of at least one encrypted email using the secure connection to the computer that received at least one encrypted email. ### Claim 21 (depends on 20) A method of encrypting email according to claim 20, where at least one public key is stored in at least one public key certificate that is self-signed using a corresponding private key. ### Claim 22 (depends on 21) A method of encrypting email according to claim 21, where the subject of at least one public key certificate is at least one of the recipient's email address. ### Claim 23 (depends on 20) A method of encrypting email according to claim 20, where the server is a secure server hosted by a trusted third party. ### Claim 24 (depends on 20) A method of encrypting email according to claim 20, where the server authenticates the recipient by examining at lest one digital certificate associated with at least one recipient ### Claim 25 (depends on 24) A method of encrypting email according to claim 24, where the server checks that at least one digital certificate associated with the recipient has been signed by a known trusted root. ### Claim 26 (depends on 24) A method of encrypting email according to claim 24, where the server compares at least one email address associated with a digital certificate that is associated with at least one recipient to at least one email address that is the same address as the email intercepted from the email sender. ### Claim 27 (depends on 20) A method of encrypting email according to claim 20, where the server authenticates at least one recipient by proving the recipient has ownership of the private key corresponding to a supplied public key. ### Claim 28 (depends on 27) A method of encrypting email according to claim 27 where the recipient's ownership of the private key is proved by requesting data from a successful private key operation. ### Claim 29 (depends on 20) A method of encrypting email according to claim 20, where the displaying of the contents of at least one encrypted email is through a web-browser on a recipient's computer. ### Claim 30 (depends on 20) A method according to claim 20 where the notification is a link sent through an email to at least one recipient. ### Claim 31 (depends on 20) A method according to claim 20 where the computer that received at least one encrypted email is the server receiving at least one private key over the first encrypted connection. ### Claim 32 (depends on 20) A method according to claim 20 where the computer that received at least one encrypted email is separate from the server receiving at least one private key over at least one encrypted connection. ### Claim 33 (depends on 32) A method according to claim 32 where the computer that received at least one encrypted email is a mail server. ### Claim 34 (depends on 20) A method according to claim 20 where the server requests at least one password from at least one recipient. ### Claim 35 (depends on 32) A method according to claim 32 where at least one password requested from at least one recipient is compared to at least one password stored on a computer separate from the server. ### Claim 36 (depends on 20) A method according to claim 20, where the notification includes at least one identifier of the email sender. ### Claim 37 (depends on 36) A method according to claim 36, where at least one identifier of the email sender an image file. ### Claim 38 A system of encrypting email comprising a server, a computer sending an email, an email, a means of intercepting the email, a private key, a means of encrypting the email using the private key, a means of establishing a secure connection between the server and the computer sending the email, a recipient, a means of establishing a secure connection between the server and the recipient; and a means of decrypting the email using the private key ### Claim 39 (depends on 38) A system according to claim 38, where the private key is generated upon the interception of the email.