Access Control and Rights ManagementLegal and Technical IssuesPowerPoint PresentationWorks for hireFair useMoral rightsGetting PermissionSlide 8Slide 9Technical issuesIssues in EncryptionMessage interceptionTypes of Encryption MethodsDancing Men????Types of encryption - 2Types of encryption - 3Monoalphabetic codesLetter distributions in EnglishDisguising frequenciesMore complexDecodingEnigmaEnigmaEnigma - 2Encryption/Decryption KeysSummary of encryption goalsData Encryption StandardSlide 28Slide 29Public Key encryptionEffective Public Key EncryptionIt all comes down to this:Rivest, Shamir, Adelman (RSA)Public Key encodingAn example:On a practical note: PGPIssuesDigital SignaturesDigital Signature basic techniquePublic key encryption with implied signatureDigital Signature Standard (DSS)Digital Signature - SHAEncryption summaryImportant methodsDigital signaturesLegal and ethical issuesAccess Control and Rights ManagementLegal and Technical Issues•Legal: When is a resource available to digitize and make available. What requirements exist for controlling access.•Technical: How do we control access to a resource that is stored online?–Policies–Encoding–Distribution limitationsDate of work Protected from TermCreated 1-1-78 or afterWhen work is fixed in tangible medium of expressionLife + 70 years1(or if work of corporate authorship, the shorter of 95 years from publication, or 120 years from creationPublished before 1923In public domain NonePublished 1923 - 63When published with notice 28 years + could be renewed for 47 years, now extended by 20 years for a total renewal of 67 years. If not so renewed, now in public domainPublished from 1964 - 77When published with notice 28 years for first term; now automatic extension of 67 years for second termCreated before 1-1-78 but not published1-1-78, the effective date of the 1976 Act which eliminated common law copyrightLife + 70 years or 12-31-2002, whichever is greaterCreated before1-1-78 but published between then and 12-31-20021-1-78, the effective date of the 1976 Act which eliminated common law copyrightLife + 70 years or 12-31-2047 whichever is greaterChart created by Lolly Gasaway. Updates at http://www.unc.edu/~unclng/public-d.htmWorks for hire•Usual case -- works created by faculty are not the property of the university. –Faculty surrender copyright to publishers of journals and books–Some publishers allow faculty to retain copyright, giving the publisher specific limited rights to reproduce and distribute the work.Fair use•No clear, easy answers.•Checksheet provided in the article is a good guide to the issues.•Link to the checksheet: http://www.copyright.iupui.edu/checklist.htmMoral rights•Fair to the creator–Keep the identity of the creator of the work–Do not cut the work–Generally, be considerate of the person (or institution) that created the work.Getting Permission•With the best will in the world, getting the appropriate permissions is not always easy.–Identify who holds the rights–Get in touch with the rights holder–Get a suitable agreement to cover the needs of your use.•Useful links: http://www.loc.gov/copyright/http://www.utsystem.edu/OGC/IntellectualProperty/PERMISSN.HTM–Connections to various ways to discover and contact the rights holder of a work.Source: NINCH Guide to Good Practice. Chapter 4: Rights ManagementChecking copyright statusSource: NINCH Guide to Good Practice. Chapter 4: Rights ManagementCopyright: Lauryn G. GrantConsidering people depicted in the workTechnical issues•Link the resource to the copyright statements•Maintain that link when the resource is copied or used•Approaches:–Steganography–Encryption–Digital Wrappers–Digital WatermarksIssues in Encryption•General cases for protection of controlled content: Concern for passive listening, active interference.–Listening: intruder gains information, may not be detected. Effects indirect. –Active interference•Intruder may prevent delivery of the message to the intended recipient.•Intruder may substitute a fake message for the intended one•Effects are direct and immediate•Less likely in the case of digital library contentMessage interceptionOriginal messageEncodingMethodCiphertextDecodingMethodReceived messageEavesdropping MasqueradingIntruder(Plain text)(Plain text)Types of Encryption Methods•Substitution–Simple adjustment, Caesar’s cipher•Each letter is replaced by one that is a fixed distance from it in the alphabet. A becomes D, B becomes E, etc. At the end, wrap around, so X becomes A, Y becomes B, Z becomes C.•May have been confusing the fist time it was done, but it would not have taken long to figure it out.–Simple substitution of other characters for letters -- numbers, dancing men, etc.–More complex substitution. No pattern to the replacement scheme. •See common cryptogram puzzles. These are usually made easier by showing the spaces between the words. (For very modern version, see http://www.cryptograms.org/)Dancing Men????•Arthur Conan Doyle: The Adventure of the Dancing Men. A Sherlock Holmes Adventure.Read the story online and see the images and analysis of the decoding at http://camdenhouse.ignisart.com/canon/danc.htm“Speaking roughly, T, A, O, I, N, S, H, R, D, and L are the numerical order in which letters occur; but T, A, O, and I are very nearly abreast of each other, and it would be an endless task to try each combination until a meaning was arrived at.”Types of encryption - 2Hiding the text.•The wax tablet example –message written on the base of the tablet and wax put over top of it with another message on the wax•Steganography: (ste-g&n-o´gr&-fē) (n.) The art and science of hiding information by embedding messages within other, seemingly harmless messages. Steganography works by replacing bits of useless or unused data in regular computer files (such as graphics, sound, text, HTML, or even floppy disks ) with bits of different, invisible information. This hidden information can be plain text, cipher text, or even images.•Special software is needed for steganography, and there are freeware versions available at any good download site.•Can be used to insert identification into a file to track its source.Definition from www.webopedia.comTypes of encryption - 3•Key-based shuffling–Using a mnemonic to make the key easy to remember.•A machine to do the shufflingADBCDCBAWhat shuffling is used?How would “CAB”