1. DKIM https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

2. Email authentication - DKIM 1 DKIM checks the message content, deploying digital signatures. Rather than using digital certificates, the keys for signature-verification are distributed via the DNS. That way, a message gets associated to a domain name. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

3. Email authentication - DKIM 1 A DKIM-compliant ADMD generates one or more pairs of Asymmetric key algorithm|asymmetric keys, then hands private keys to the signing MTA, and publishes public keys on the DNS https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

4. Email authentication - DKIM 1 The purpose of a DKIM-signature is not to assure message integrity. Often, it does not even guarantee that a message author's data, as per a signed From: field, has a real name or a valid mailbox. The parts to be signed are chosen so as to identify the message unequivocally. A valid signature just states that the message did actually flow through a box operated by that ADMD. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

5. Email authentication - DKIM 1 While intermediate relays usually can add header fields without breaking existing DKIM-signatures, changing character set, adding a tag to the subject, adding a footer, or fixing the MIME structure of a message are likely to break them https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

6. Dkim 1 'DomainKeys Identified Mail' ('DKIM') is an email validation system designed to detect email spoofing by providing a mechanism to allow receiving mail exchangers to check that incoming mail from a domain name|domain is authorized by that domain's administrators. A digital signature included with the message can be validated by the recipient using the signer's public-key cryptography|public key published in domain name system|the DNS. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

7. Dkim 1 DKIM is the result of merging 'DomainKeys' and 'Internet Identified Mail'. This merged specification has been the basis for a series of IETF #External links|standards-track specifications and support documents which eventually resulted in Internet standard|STD [http://datatracker.ietf.org/doc/STD76?inclu de_text=1 76]. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

8. Dkim 1 [http://blog.fastmail.fm/2009/08/13/all- outbound-email-now-being-dkim-signed/ All outbound email now being DKIM signed] https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

9. Dkim - Overview 1 In most cases, the signing module acts on behalf of the 'author' organization or the originating service provider by inserting a 'DKIM-Signature:' header field https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

10. Dkim - Overview 1 DKIM is independent of Simple Mail Transfer Protocol (SMTP) routing aspects in that it operates on the RFC 5322 message -- the transported mail's header and body -- not the SMTP envelope defined in RFC 5321. Hence the DKIM signature survives basic relaying across multiple MTAs. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

11. Dkim - Overview 1 DKIM allows the signer to distinguish its legitimate mail stream. It does not directly prevent or disclose abusive behavior. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

12. Dkim - Overview 1 This ability to distinguish legitimate mail from potentially forged mail has benefits for recipients of e-mail as well as senders, and DKIM awareness is programmed into some e-mail software. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

13. Dkim - How it works 1 The DKIM-Signature header field consists of a list of tag=value parts https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

14. Dkim - How it works 1 Note that the DKIM-Signature header field itself is always implicitly included in 'h'. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

15. Dkim - Development 1 In September 2011, RFC 6376 merged and updated the latter two documents, while preserving the substance of the DKIM protocol https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

16. Dkim - Development 1 DKIM was initially produced by an informal industry consortium and was then submitted for enhancement and standardization by the IETF DKIM Working Group, chaired by Barry Leiba and Stephen Farrell, with https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

17. Dkim - Development 1 Source code development of one common library is led by 'The OpenDKIM Project', following the most recent protocol additions, and licensing under the BSD licenses#3-clause license (New BSD License)|New BSD License. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

18. Dkim - Patent encumbrance 1 DomainKeys is covered by assigned to Yahoo! Inc. For the purpose of the DKIM IETF Working Group, Yahoo! released the now obsolete DK library under a dual license scheme: the DomainKeys Patent License Agreement v1.2, an unsigned version of which can still be found, and GNU General Public License v2.0 (and no other version). https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

19. Dkim - Advantages 1 * It allows a great reduction in abuse desk work for DKIM-enabled domains if e-mail receivers use the DKIM system to identify forged e-mail messages claiming to be from that domain. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

20. Dkim - Use with spam filtering 1 However, widespread use of DKIM can prevent spammers from forging the source address of their messages, a technique they commonly employ today. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

21. Dkim - Anti-phishing 1 DKIM can be useful as an anti-phishing technology. Mailers in heavily phished domains can sign their mail to show that it is https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

22. Dkim - Anti-phishing 1 genuine. Recipients can take the absence of a valid signature on mail from those domains to be an indication that the mail is probably forged. The best way to determine the set of domains that merit this degree of scrutiny remains an open question; DKIM has an optional feature called Author Domain Signing Practices|ADSP that lets authors that sign all their mail self-identify, but the effectiveness of this approach remains questionable: https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

23. Dkim - Anti-phishing 1 Working with eBay and PayPal, Google has effectively utilized DKIM in GMail in such a way that any e-mail that claims to be coming from ebay.com or PayPal.com will not be accepted at all if they cannot be verified successfully with DKIM. Such messages won't even appear in the Spam folder. Heavily phished domains that deserve such treatment are few in number, far less than those who publish strict policies. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

24. Dkim - Compatibility 1 Because it is implemented using DNS records and an added RFC 5322 header field, DKIM is compatible with the existing e-mail infrastructure. In particular, it is transparent to existing e-mail systems that lack DKIM support. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

25. Dkim - Protocol overhead 1 DKIM requires cryptographic checksums to be generated for each message sent through a mail server, which results in overhead (computing)|computational overhead not otherwise required for e-mail delivery https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

26. Dkim - Protocol overhead 1 This facet of DKIM may look similar to hashcash, except that the receiver side verification is not a negligible amount of work. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

27. Dkim - Weaknesses 1 DKIM signatures do not encompass the message envelope, which holds the return-path and https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

28. Dkim - Weaknesses 1 message recipients. Since DKIM does not attempt to protect against mis-addressing, this does not affect its utility. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

29. Dkim - Arbitrary forwarding 1 As mentioned above, authentication is not the same as abuse prevention: DKIM doesn't prevent a spammer from composing an ad at a reputable domain so as to obtain a signed copy of the message https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

30. Dkim - Content modification 1 in format=flowed the quotes can be legally removed, which breaks DKIM signatures https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

31. Dkim - Content modification 1 The OpenDKIM Project organized a data collection involving 21 mail servers and millions of messages. Only '92.3% of observed signatures were successfully verified', a success rate that drops slightly (90.5%) when only mailing list traffic is considered. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

32. Dkim - Annotations by mailing lists 1 These problems are exacerbated when filtering or relaying software adds actual changes to a message. Although legitimate, the footer addition operated by most Electronic mailing list|mailing lists and many central Antivirus software|antivirus solutions, formally, are exactly the kind of message tampering that DKIM has been designed to guard against. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

33. Dkim - Annotations by mailing lists 1 by DKIM. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

34. Dkim - Annotations by mailing lists 1 Some suggest that these limitations could be addressed by combining DKIM with SPF, because SPF (which breaks when messages are forwarded) is immune to modifications of the e-mail data, and mailing lists typically use their own SMTP error address, also known as Return-Path. In short, SPF works without problems where DKIM might run into difficulties, and vice versa. https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

35. Dkim - 2012 usage vulnerability 1 [http://www.wired.com/threatlevel/2012/10/ dkim-vulnerability-widespread How a Google Headhunter’s E-Mail Unraveled a Massive Net Security Hole] https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

36. For More Information, Visit: https://store.theartofservice.co m/itil-2011-foundation- complete-certification-kit- fourth-edition-study-guide- ebook-and-online-course.html https://store.theartofservice.co m/itil-2011-foundation- complete-certification-kit- fourth-edition-study-guide- ebook-and-online-course.html The Art of Service https://store.theartofservice.com