[ Pobierz całość w formacie PDF ]
.Ï%ýÿ Enabling the default Administrator account to beThe policy might also prohibit users from employýÿlocked out for interactive logons on all computersing parts of their names, addresses, or phone numýÿexcept domain controllersbers in passwords.See Also: account lockout, Passfilt.dll, passwordÏ%ýÿ Enforcing a password policy using operating sysýÿtem features or add-on products.For example, inpassword Microsoft Windows 2000, administrators can con-A string of characters used to verify the identity of a figure Password Policy, a part of Local Securityuser logging on to an application, system, or network.Policy, to enforce such settings as minimum pass-word length or complexity.235 Password Authentication Protocol (PAP) password-based encryption (PBE)Ï%ýÿ Educating users about passwords by providingPassword Authenticationthem with guidelines about how to create goodProtocol (PAP)passwords.A common suggestion for creating goodA remote access authentication protocol supported bypasswords is to think of a phrase and then use thePoint-to-Point Protocol (PPP).first letter of each word to form the password.Forexample, the phrase  I feel really bad for the way IOverviewtreated you might generate the passwordPassword Authentication Protocol (PAP) is the simplest ifRB4twity if the user in fact felt  really bad inauthentication protocol supported by PPP and transmitsthis instance.Users should also be discouragedthe user s credentials (user name and password) overfrom using things like pets names or favorite movýÿthe connection in cleartext.As a result, PAP is also theies as the basis for forming passwords and fromleast secure PPP authentication method and generallythinking that by adding a simple numeric  123 toshould not be used unless the client and access serverthe end of a word a secure password results.Userscannot negotiate a more secure authentication protocolshould also be educated to guard againstlike Challenge Handshake Authentication Protocolsocial-engineering attacks and to never give out(CHAP) or Microsoft Challenge Handshake Authentiýÿtheir passwords except to known administrators orcation Protocol (MS-CHAP).As outlined in RFC 1334,technical support people.support for PAP is mandatory in PPP, but in practice it isusually needed only for connecting to olderÏ%ýÿ Requiring that users change their passwords freýÿUNIX-based access servers that do not support otherquently either by creating a written policy or bymethods of authentication.enforcing the requirement in the operating system.Note that this can sometimes have the oppositeSee Also: authentication, passwordeffect, however, because users may find it more difýÿficult to remember which password is their currentpassword-basedone and may therefore be more tempted to writeencryption (PBE)passwords down and keep them close at hand.A method for generating a cryptographic key from aBecause of the weakness of simple password-protectedpassword.authentication, many businesses augment such systemsOverviewwith additional security measures, including smartPPassword-based encryption (PBE) algorithms arecards and biometric identification systems.A high-schemes that use passwords to generate secret keys forsecurity environment might employ three-factor authentiýÿpurposes of secrecy and data integrity.PBE algorithmscation in which a user must enter a password, insert aare commonly used for secure storage of files or forsmart card, and allow an iris scan in order to obtain accessprotecting a user s private key store on a system, butto the network.Such systems are far more difficult tothey also can be used for encrypting and signing elecýÿcrack than simple password-protected networks.tronic messages.Two public key cryptography stanýÿNotesdards (PKCSs) from RSA Security, PKCS #5 and #12,Many hardware devices such as routers come withdefine PBE algorithms that can be used for generatingdefault passwords that should be changed when thesecret keys from passwords.device is installed to protect against compromise.ImplementationSee Also: authentication, biometric identification,In a typical PBE scheme, the user s password isone-time password (OTP), passphrase, passwordappended with a salt, a pseudorandom number used tocracking, smart cardenlarge the space of possible passwords to reduce thesusceptibility of the algorithm to brute-force key236 password cracking password crackingsearch.The combination of password and salt is then Implementationhashed using a cryptographic hashing algorithm such as Password crackers guess passwords using two mainmessage digest 5 (MD5) or Secure Hash Algorithm-1 techniques:(SHA-1) to produce the secret key used for encryption.Ï%ýÿ Dictionary attack: This involves trying all wordsIn some schemes the hashing function is iterativelyin a dictionary (a list of words typically used forapplied a number of times to make it more difficult topasswords) to see if a valid match can be found.crack the resulting key [ Pobierz caÅ‚ość w formacie PDF ]

  • zanotowane.pl
  • doc.pisz.pl
  • pdf.pisz.pl
  • hanula1950.keep.pl

    		•