CONTROLLING TRANSMISSION OF UNAUTHORIZED UNOBSERVABLE CONTENT IN EMAIL USING POLICY

• US 20100180027A1
• Filed: 01/10/2009
• Published: 07/15/2010
• Est. Priority Date: 01/10/2009
• Status: Abandoned Application

• Current Assignee: Barracuda Networks Incorporated
• Original Assignee: Barracuda Networks Incorporated
• Inventors: DRAKO, DEAN
• Application Number:
  US12/351,812
• Publication Number:
  US 20100180027A1
• Time in Patent Office: Days
• US Class Current: 709/225
• CPC Class Codes: G06F 21/60 Protecting data
• CPC Class Codes: H04L 51/212 using filtering or selective blocking
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 9/30 Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy

Abstract

A system, method, and apparatus is disclosed to control mail server in handling encrypted messages.

Claims

1. An apparatus for controlling email transmission of encrypted content comprising

an email receiver circuit to receive an electronic mail message

an email analysis circuit to determine if an electronic mail message contains unauthorized encrypted content,

an email transmitter circuit and

an encrypted email block circuit.

2. The apparatus of claim 1 wherein a block circuit comprises a circuit to forward the email to an administrative or security account.

3. The apparatus of claim 1 wherein a block circuit comprises a circuit to delete the encrypted content and replace it with a warning message.

4. The apparatus of claim 1 wherein a block circuit comprises a circuit to complete the smtp handshake and to store the email.

5. The apparatus of claim 1 wherein a block circuit comprises a circuit to return a smtp reply code in the 400-555 range.

6. The apparatus of claim 1 wherein the email analysis circuit further comprises a policy circuit to determine if an email shall be transferred to the block circuit by applying a policy and wherein any circuit of claim 1 comprises a processor controlled by software instructions.

7. The apparatus of claim 6 wherein a policy defines any encrypted content as unauthorized encrypted content.

8. The apparatus of claim 6 wherein a policy depends on a role of sender within an entity.

9. The apparatus of claim 6 wherein a policy depends on a organizational department of sender.

10. The apparatus of claim 6 wherein a policy depends on a hierarchical level of a sender within an entity.

11. The apparatus of claim 6 wherein a policy depends on time of day and day of week of the electronic mail message.

12. The apparatus of claim 6 wherein a policy depends on a digital signature of the sender.

13. The apparatus of claim 6 wherein a policy depends on a public key of the sender.

14. A computer-implemented method comprising controlling a processor to perform the steps of

opening an smtp body,

scanning for a string comprising - - - BEGIN PGP MESSAGE - - -

scanning for a block of text;

scanning far a string comprising - - - END PGP MESSAGE - - - , and

applying a policy to determine a selected disposition of the smtp body.

15. The method of claim 14 wherein a selected disposition of the smtp body comprises replacing the block of text with the string “

NO ENCRYPTED CONTENT ALLOWED”

.

16. A computer-implemented method comprising controlling a processor to perform the steps of

opening an smtp message, and

applying a policy to determine a selected disposition of the smtp message.

17. The method of claim 16 wherein a selected disposition of the smtp message comprises deleting the message.

18. The method of claim 16 wherein a policy comprises disposing of a message if a header of an smtp message contains a string comprising application/x-pkcs7-mime;

name=“

smime.p7m”

.

19. The method of claim 16 wherein a policy defines any encrypted content as unauthorized encrypted content.

20. The method of claim 16 wherein a policy depends on a role of sender within an entity.

21. The method of claim 16 wherein a policy depends on a organizational department of sender.

22. The method of claim 16 wherein a policy depends on a hierarchical level of a sender within an entity.

23. The method of claim 16 wherein a policy depends on a certain approved encryption from a certain host computer.

24. The method of claim 16 wherein a policy depends on a digital signature of the sender.

25. The method of claim 16 wherein a policy depends on id code within a database of authorized encrypted message id codes.

26. A computer-implemented method comprising controlling a processor to perform the steps of

opening a message body,

performing a statistical analysis on the number of characters between full stops,

performing a statistical analysis on the number of characters between spaces, and

counting the percentage of words recognized by a dictionary program and

applying a policy to determine a selected disposition of the message body.

27. The method of claim 26 wherein a policy is to dispose of the message body if it is statistically different from any natural language statistical analysis and percentage.

28. A computer-implemented method comprising controlling a processor to perform the steps of reading a file extension of a file attached to an email and deleting the email if the file extension is an encrypted file extension.

29. The method of claim 28 wherein an encrypted file extension is one selected from the group following:

file extension abiABI-Software Development coder

file extension aclArchiCrypt Live secured data file

file extension aexArmored extracted public encryption key

file extension aexpkArmored extracted public key

file extension afpFileProtector encrypted file

file extension afs3AFS 3 Basic encrypted file

file extension apvPassword file

file extension apwpassword file

file extension attZipLip secure e-mail

file extension binMacbinary II encoded file

file extension bin64Binary encoding method (used by mime complient mail readers)

file extension canCan Encryptor/Decryptor encrypted file

file extension cfeCryptoForge encrypted file

file extension cptCCRYPT encrypted file

file extension cptdBASE encrypted memo file

file extension cxtAdobe Director protected cast file

file extension czipZG encrypted zip archive

file extension dc4ViaThinkSoft (De)Coder file

file extension docenxEgis encrypted Word DOC file

file extension docxenxEgis encrypted Word Open XML DOCX file

file extension dotmenxEgis encrypted DOTM (Word

     2007) file

file extension dotxenxEgis encrypted DOTX (Word

     2007) file

file extension dpdDekart Private Disk encrypted disk image

file extension dsfPC-TRUST document signer

file extension eccEssential Taceo crypto container

file extension ecrEcrypt encrypted file

file extension eeEncrypt Easy encrypted file

file extension efaEcrypt 2005 encrypted file

file extension eflEncryptafile encrypted file

file extension efrEncryptafile Private Key file

file extension efuEncryptafile Public Key file

file extension egisenxEgis encryped file

file extension encEncoded file—

UUENCODEd file (Lotus 1-2-3—

uuencode)

file extension encCopySafe PDF encrypted file

file extension encMedia Safe encrypted data

file extension encMy Personal Programmer encrypted distributed project

file extension entEntrust Entelligence secured file

file extension esmEuropay security module

file extension fshCoolfish encrypted file

file extension gifenxEgis encrypted GIF file

file extension grdStrongDisk Encrypted Disk Image

file extension hpgHide Photos encrypted photo container

file extension htmlenxEgis encrypted HTML file

file extension icaldentity Compass encrypted answers

file extension ifsInfoSlips secure information package

file extension ismSimulationX encrypted model

file extension jpegenxEgis encrypted JPEG file

file extension jpgenxEgis encrypted JPG file

file extension jrltop Secret Crypto Gold top secret journal file

file extension keyAvira AntiVir Personal license key file

file extension keySentry 2020 encryption file

file extension mfsMetFS encrypted FUSE based filesystem file

file extension mhtenxEgis encrypted HTM file

file extension mhtmlenxEgis encrypted MHTML file

file extension mimMulti-Purpose Internet Mail Extensions file

file extension mmeMime encoded

file extension p7Elemica eSignature application

file extension p7bSPC file—

cryptographic certificate

file extension p7mPKCS #7 MIME Message

file extension pc2PrivateChat! file

file extension pdeEncrypted file

file extension pdfenxEgis encrypted PDF file

file extension pemPrivacy Enhanced Mail security certificate

file extension pempidgin instant messenger certification file

file extension pfAladdin Systems private file

file extension pfxPersonal Information Exchange

file extension pfxCertificate File

file extension pi2Studio2 high resolution encrypted image

file extension ppkPuTTY Win32 Telnet/SSH client private key

file extension ppsxenxEgis encrypted Powerpoint Open XML PPSX file

file extension pptxenxEgis encrypted Powerpoint Open XML PPTX file

file extension pwlWindows Password file

file extension qzeQZip encrypted file

file extension rarenxEgis encrypted RAR file

file extension rawsentry 2020 encryption file

file extension rifFutuRUG encrypted resident information file

file extension rsaPKCS7 signature file

file extension rzkFile Crypt password file

file extension rzxFile Crypt encrypted file

file extension sefEncryptafile digital signature file

file extension sefsteganos encrypted file

file extension shyShyFile encrypted file

file extension spdSpyProof! encrypted disk data

file extension stm Navy'"'"'s NOWS secure login file

file extension txtenxEgis encrypted TXT file

file extension uuUuencodeed file archive (ascii)

file extension xiamenxEgis encrypted XLAM (Excel

     2007) file

file extension xlsxenxEgis encrypted Excel Open XML XLSX file

file extension zbdZebedee encrypted file

file extension zipenxEgis encrypted ZIP file.

30. A computer-implemented method comprising controlling a processor to perform the step of checking the initial and final bytes of a file attached to an email for consistency with its file extension.