CONTROLLING TRANSMISSION OF UNAUTHORIZED UNOBSERVABLE CONTENT IN EMAIL USING POLICY
A system, method, and apparatus is disclosed to control mail server in handling encrypted messages.
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.