Slide 1Privacy and SecurityAccidental Security ThreatsDeliberate Security Threats-SourcesDeliberate Security Threats-methodsSecurity PlanAuthenticationUser ProfilesOther Authentication ProceduresAuthorizationAccess ControlSecurity MechanismsEncryptionDES and AESSlide 15SQL Authorization LanguageGRANT StatementREVOKEStatistical DatabasesStatistical DB SecurityNeed for DB Security on the InternetTechniques for Internet SecurityFirewallsCertification Authorities-SSL & S-HTTPSETDigital SignaturesCSC 3800 Database Management SystemsTime: 1:30 to 2:20 Meeting Days: MWF Location: Oxendine 1237BTextbook: Databases Illuminated, Author: Catherine M. Ricardo, 2004, Jones & Bartlett PublishersFall 2009Chapter 9Database SecurityDr. Chuck LilliePrivacy and SecurityPrivacy and SecurityDatabase security◦protecting the database from unauthorized access, modification, or destructionPrivacy◦the right of individuals to have some control over information about themselves◦protected by law in many countriesRight to privacy can be protected by database securityAccidental Security Accidental Security ThreatsThreatsUser errors◦User unintentionally requests object or operation for which he/she should not be authorizedCommunications system errors◦User sent a message that should be sent to another user ◦system connects a user to a session that belongs to another user with different access privilegesOS errors◦Accidentally overwrites files and destroys part of database◦Fetches the wrong files and sends them to the user◦Fails to erase files that should be erasedDeliberate Security Threats-Deliberate Security Threats-SourcesSourcesUser intentionally gains unauthorized access and/or performs unauthorized operations on the database Disgruntled employee who is familiar with the organization's computer system seeks revengeIndustrial spies seek information for competitorsDeliberate Security Threats-Deliberate Security Threats-methodsmethodsWiretapping of communication linesElectronic eavesdropping-picking up electronic signals Reading display screens or printouts left unsupervised Impersonating authorized users or users with greater access Writing programs to bypass the DBMS and access database data directlyWriting applications programs that perform unauthorized operations Deriving information about hidden data by clever querying Removing physical storage devices from the computer facilityMaking copies of stored files without going through the DBMSBribing, blackmailing or influencing authorized users to obtain information or damage the databaseSecurity PlanSecurity PlanShould begin with physical security measures for the building-physical barriers, control access, require badges, sign-in etc.Should have more physical security for the computer facilities-e.g. locked doorAdditional security control for databaseAuthenticationAuthenticationUser authentication - verifying the identity of usersOperating system uses user profiles, user ids, passwords, authentication procedures, badges, keys, or physical characteristics of the userAdditional authentication can be required to access the database-additional user ID, PWUser ProfilesUser ProfilesSystem has a user profile for each id, giving information about the userStored profiles should be kept secure, possibly in encrypted formProfile normally includes a password, allegedly known only to the userPasswords should be kept secret and changed frequentlySystem should never display passwords at sign-in timeOther Authentication Other Authentication ProceduresProceduresPassword limitations-users write them down, choose words that are easy to guess, or share themCould require users to insert badges or keys to log on to a workstationVoice, fingerprints, retina scans, or other physical characteristics can be usedAuthentication procedure can be series of questions-takes longer and is more difficult to reproduce than PWAuthentication can be required again at the database User should be required to produce an additional PW to access the databaseAuthorizationAuthorizationDBMSs designed for multiple users have a security subsystemProvide for authorization-users are assigned rights to use database objectsAuthorization language-allows the DBA to write authorization rules specifying which users have what type of access to database objectsAccess ControlAccess ControlAccess control covers the mechanisms for implementing authorizationsAccess control matrix◦Planning tool to identify operations different users are permitted to perform on various database objects◦List users in left column; objects on top row; write operations permitted at intersectionDBA can delegate authorization powers to others-requires careful planning to avoid abuseSecurity MechanismsSecurity MechanismsViews-simple method for access controlSecurity log-journal for storing records of attempted security violationsAudit trail-records all access to the database -requestor, operation performed, workstation used, time, data items and values involvedTriggers can be used to set up an audit trailEncryption of database data also protects itEncryptionEncryptionUses a cipher system that consists of ◦Encryption algorithm that converts plaintext into ciphertext◦Uses encrypting key◦Decryption algorithm that reproduces plaintext from ciphertext◦Uses decryption keyWidely-used schemes for encryption◦Data Encryption Standard (DES) and Advanced Encryption Standard (AES)uses a standard algorithm, which is often hardware implemented◦Public key encryption-uses a product of primes as a public key, and the prime factors of the product as a private key Ex. RSA, named for its developers Rivest, Shamir and AdlemanDES and AESDES and AESData Encryption Standard-DES See Figure 9.4◦National Bureau of Standards, 1977◦Algorithm is public-can have hardware implementation◦Key is private◦Uses symmetric encryption-decryption key is the same as the encryption key and decryption algorithm is the inverse of encryption algorithm◦Uses 56-bit key on 64-bit blocks of plaintext, producing 64-bit blocks of ciphertext◦In each block, characters are substituted and rearranged according to the value of the key◦Two major challenges with the DES system: key security and ease of cracking the codeAdvanced Encryption Standard-AES◦Developed in 2000◦symmetric scheme; more
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