{"id":758,"date":"2021-01-17T05:39:13","date_gmt":"2021-01-16T18:05:38","guid":{"rendered":"https:\/\/exampracticetests.com\/ISC\/SSCP\/systems-security-certified-practitioner-sscp-question0750\/"},"modified":"2021-01-17T05:44:38","modified_gmt":"2021-01-17T05:44:38","slug":"systems-security-certified-practitioner-sscp-question0750","status":"publish","type":"post","link":"https:\/\/exampracticetests.com\/ISC\/SSCP\/systems-security-certified-practitioner-sscp-question0750\/","title":{"rendered":"Systems Security Certified Practitioner &#8211; SSCP &#8211; Question0750"},"content":{"rendered":"<div class=\"question\">Which of the following statements pertaining to block ciphers is incorrect? <br \/><strong><br \/>A.<\/strong> It operates on fixed-size blocks of plaintext. <br \/><strong>B.<\/strong> It is more suitable for software than hardware implementations. <br \/><strong>C.<\/strong> Plain text is encrypted with a public key and decrypted with a private key. <br \/><strong>D.<\/strong> Some Block ciphers can operate internally as a stream.<\/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>C<\/strong><\/div>\n<p><strong>Explanation:<\/strong> <\/p>\n<div class=\"explanation\">\nBlock ciphers do not use public cryptography (private and public keys). Block ciphers is a type of symmetric-key encryption algorithm that transforms a fixed-size block of plaintext (unencrypted text) data into a block of ciphertext (encrypted text) data of the same length. They are appropriate for software implementations and can operate internally as a stream. See more info below about DES in Output Feedback Mode (OFB), which makes use internally of a stream cipher.<br \/>\nThe output feedback (OFB) mode makes a block cipher into a synchronous stream cipher. It generates keystream blocks, which are then XORed with the plaintext blocks to get the ciphertext. Just as with other stream ciphers, flipping a bit in the ciphertext produces a flipped bit in the plaintext at the same location. This property allows many error correcting codes to function normally even when applied before encryption.<br \/>\nReference(s) used for this question: Wikipedia on Block Cipher mode at: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Block_cipher_mode_of_operation\" title=\"External link\" rel=\"nofollow noopener\" target=\"_blank\">https:\/\/en.wikipedia.org\/wiki\/Block_cipher_mode_of_operation<\/a> and <a href=\"http:\/\/www.itl.nist.gov\/fipspubs\/fip81.htm\" title=\"External link\" rel=\"nofollow noopener\" target=\"_blank\">http:\/\/www.itl.nist.gov\/fipspubs\/fip81.htm<\/a><\/div>\n<p><\/strong><\/span> <\/div>\n","protected":false},"excerpt":{"rendered":"<p>Which of the following statements pertaining to block ciphers is incorrect? A. It operates on fixed-size blocks of plaintext. B. It is more suitable for software than hardware implementations. C. Plain text is encrypted with a public key and decrypted with a private key. D. Some Block ciphers can operate internally as a stream. Show [&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":[1078,753,3],"class_list":["post-758","post","type-post","status-publish","format-standard","hentry","category-systems-security-certified-practitioner-sscp","tag-choices","tag-question-0750","tag-systems-security-certified-practitioner-sscp"],"_links":{"self":[{"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/posts\/758","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=758"}],"version-history":[{"count":1,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/posts\/758\/revisions"}],"predecessor-version":[{"id":1834,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/posts\/758\/revisions\/1834"}],"wp:attachment":[{"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/media?parent=758"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/categories?post=758"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exampracticetests.com\/ISC\/SSCP\/wp-json\/wp\/v2\/tags?post=758"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}