{"id":704,"date":"2021-01-17T05:38:15","date_gmt":"2021-01-16T18:04:38","guid":{"rendered":"https:\/\/exampracticetests.com\/ISC\/SSCP\/systems-security-certified-practitioner-sscp-question0696\/"},"modified":"2021-01-17T05:44:34","modified_gmt":"2021-01-17T05:44:34","slug":"systems-security-certified-practitioner-sscp-question0696","status":"publish","type":"post","link":"https:\/\/exampracticetests.com\/ISC\/SSCP\/systems-security-certified-practitioner-sscp-question0696\/","title":{"rendered":"Systems Security Certified Practitioner &#8211; SSCP &#8211; Question0696"},"content":{"rendered":"<div class=\"question\">What is NOT an authentication method within IKE and IPsec? <br \/><strong><br \/>A.<\/strong> CHAP <br \/><strong>B.<\/strong> Pre shared key <br \/><strong>C.<\/strong> certificate based authentication <br \/><strong>D.<\/strong> Public key authentication<\/div>\n<p><\/p>\n<style> .hidden-div{ display:none } <\/style>\n<p>\t\t\t\t\t\t\t<button onclick=\"getElementById('hidden-div').style.display = 'block'\"> Show Answer <\/button> <button onclick=\"getElementById('hidden-div').style.display = 'none'\">Hide Answer<\/button><\/p>\n<div class=\"hidden-div\" id=\"hidden-div\"><span style=\"\"><\/p>\n<div class=\"answer\">Correct Answer: <strong>A<\/strong><\/div>\n<p><strong>Explanation:<\/strong> <\/p>\n<div class=\"explanation\">\nCHAP is not used within IPSEC or IKE. CHAP is an authentication scheme used by Point to Point Protocol (PPP) servers to validate the identity of remote clients. CHAP periodically verifies the identity of the client by using a three-way handshake. This happens at the time of establishing the initial link (LCP), and may happen again at any time afterwards. The verification is based on a shared secret (such as the client user&#8217;s password).<br \/>\nAfter the completion of the link establishment phase, the authenticator sends a &#8220;challenge&#8221; message to the peer. The peer responds with a value calculated using a one-way hash function on the challenge and the secret combined. The authenticator checks the response against its own calculation of the expected hash value. If the values match, the authenticator acknowledges the authentication; otherwise it should terminate the connection. At random intervals the authenticator sends a new challenge to the peer and repeats steps 1 through 3.<br \/>\nThe following were incorrect answers:<br \/>\nPre Shared Keys In cryptography, a pre-shared key or PSK is a shared secret which was previously shared between the two parties using some secure channel before it needs to be used. To build a key from shared secret, the key derivation function should be used. Such systems almost always use symmetric key cryptographic algorithms. The term PSK is used in WiFi encryption such as WEP or WPA, where both the wireless access points (AP) and all clients share the same key.<br \/>\nThe characteristics of this secret or key are determined by the system which uses it; some system designs require that such keys be in a particular format. It can be a password like &#8216;bret13i&#8217;, a passphrase like &#8216;Idaho hung gear id gene&#8217;, or a hexadecimal string like &#8217;65E4 E556 8622 EEE1&#8242;. The secret is used by all systems involved in the cryptographic processes used to secure the traffic between the systems. Certificat Based Authentication<br \/>\nThe most common form of trusted authentication between parties in the wide world of Web commerce is the exchange of certificates. A certificate is a digital document that at a minimum includes a Distinguished Name (DN) and an associated public key.<br \/>\nThe certificate is digitally signed by a trusted third party known as the Certificate Authority (CA). The CA vouches for the authenticity of the certificate holder. Each principal in the transaction presents certificate as its credentials. The recipient then validates the certificate\u2019s signature against its cache of known and trusted CA certificates. A \u201cpersonal certificate\u201d identifies an end user in a transaction; a \u201cserver certificate\u201d identifies the service provider.<br \/>\nGenerally, certificate formats follow the X.509 Version 3 standard. X.509 is part of the Open Systems Interconnect (OSI) X.500 specification.<br \/>\nPublic Key Authentication Public key authentication is an alternative means of identifying yourself to a login server, instead of typing a password. It is more secure and more flexible, but more difficult to set up.<br \/>\nIn conventional password authentication, you prove you are who you claim to be by proving that you know the correct password. The only way to prove you know the password is to tell the server what you think the password is. This means that if the server has been hacked, or spoofed an attacker can learn your password.<br \/>\nPublic key authentication solves this problem. You generate a key pair, consisting of a public key (which everybody is allowed to know) and a private key (which you keep secret and do not give to anybody). The private key is able to generate signatures. A signature created using your private key cannot be forged by anybody who does not have a copy of that private key; but anybody who has your public key can verify that a particular signature is genuine.<br \/>\nSo you generate a key pair on your own computer, and you copy the public key to the server. Then, when the server asks you to prove who you are, you can generate a signature using your private key. The server can verify that signature (since it has your public key) and allow you to log in. Now if the server is hacked or spoofed, the attacker does not gain your private key or password; they only gain one signature. And signatures cannot be re-used, so they have gained nothing.<br \/>\nThere is a problem with this: if your private key is stored unprotected on your own computer, then anybody who gains access to your computer will be able to generate signatures as if they were you. So they will be able to log in to your server under your account. For this reason, your private key is usually encrypted when it is stored on your local machine, using a passphrase of your choice. In order to generate a signature, you must decrypt the key, so you have to type your passphrase.<br \/>\nReferences: RFC 2409: The Internet Key Exchange (IKE); DORASWAMY, Naganand &#038; HARKINS, Dan<br \/>\nIpsec: The New Security Standard for the Internet, Intranets, and Virtual Private Networks, 1999, Prentice Hall PTR; SMITH, Richard E. Internet Cryptography, 1997, Addison-Wesley Pub Co.; HARRIS, Shon, All-In-One CISSP Certification Exam Guide, 2001, McGraw-Hill\/Osborne, page 467.<br \/>\n<a href=\"http:\/\/en.wikipedia.org\/wiki\/Pre-shared_key\" title=\"External link\" rel=\"nofollow noopener\" target=\"_blank\">http:\/\/en.wikipedia.org\/wiki\/Pre-shared_key<\/a> <a href=\"http:\/\/www.home.umk.pl\/~mgw\/LDAP\/RS.C4.JUN.97.pdf\" title=\"External link\" rel=\"nofollow noopener\" target=\"_blank\">http:\/\/www.home.umk.pl\/~mgw\/LDAP\/RS.C4.JUN.97.pdf<\/a> <a href=\"http:\/\/the.earth.li\/~sgtatham\/putty\/0.55\/htmldoc\/Chapter8.html#S8.1\" title=\"External link\" rel=\"nofollow noopener\" target=\"_blank\">http:\/\/the.earth.li\/~sgtatham\/putty\/0.55\/htmldoc\/Chapter8.html#S8.1<\/a><\/div>\n<p><\/strong><\/span> <\/div>\n","protected":false},"excerpt":{"rendered":"<p>What is NOT an authentication method within IKE and IPsec? A. CHAP B. Pre shared key C. certificate based authentication D. Public key authentication Show Answer Hide Answer Correct Answer: A Explanation: CHAP is not used within IPSEC or IKE. CHAP is an authentication scheme used by Point to Point Protocol (PPP) servers to validate [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[1078,699,3],"class_list":["post-704","post","type-post","status-publish","format-standard","hentry","category-systems-security-certified-practitioner-sscp","tag-choices","tag-question-0696","tag-systems-security-certified-practitioner-sscp"],"_links":{"self":[{"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/posts\/704","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/comments?post=704"}],"version-history":[{"count":1,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/posts\/704\/revisions"}],"predecessor-version":[{"id":1780,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/posts\/704\/revisions\/1780"}],"wp:attachment":[{"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/media?parent=704"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/categories?post=704"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/tags?post=704"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}