信息安全工程師
為了更好的用戶體驗,并能正常使用所有功能,我們建議您使用 Chrome瀏覽器(點擊下載>>)

王牌战士介绍 > 軟考 > 信息安全工程師 > 2019年信息安全工程師上午基礎知識真題(八)

王牌战士短信:2019年信息安全工程師上午基礎知識真題(八)

  • 胡媛
  • 信息安全工程師
  • 2019-05-27
  • 信息安全工程師交流群: 626232680
摘要: 希賽網軟考頻道小編為大家整理了2019年信息安全工程師上午基礎知識真題第八部分,供大家參考。

王牌战士介绍 www.hsfgm.icu 71-75、The modern study of symmetric-key ciphers relates mainly to the study of block ciphers and stream ciphers and to their applications. A block cipher is, in a sense, a modern embodiment of Alberti's polyalphabetic cipher: block ciphers take as input a block of (71 )and a key, and output a block of ciphertext of the same size. Since messages are almost always longer than a single block, some method of knitting together successive blocks is required. Several have been developed, some with better security in one aspect or another than others. They are the mode of operations and must be carefully considered when using a block cipher in a cryptosystem.

The Data Encryption Standard (DES) and the Advanced Encryption Standard (AES) are( 72 )designs which have been designated cryptography standards by the US government (though DES's designation was finally withdrawn after the AES was adopted). Despite its deprecation as an official standard, DES (especially its still-approved and much more secure triple-DES variant) remains quite popular; it is used across a wide range of applications, from ATM encryption to e-mail privacy and secure remote access. Many other block ciphers have been designed and released, with considerable variation in quality. Many have been thoroughly broken. See Category: Block ciphers.

Stream ciphers, in contrast to the ‘block’type, create an arbitrarily long stream of key material, which is combined ( 73 )the plaintext bit-by-bit or character-by-character, somewhat like the one-time pad. In a stream cipher, the output( 74 )is created based on an internal state which changes as the cipher operates. That state change is controlled by the key, and, in some stream ciphers, by the plaintext stream as well. RC4 is an example of a well-known, and widely used, stream cipher; see Category: Stream ciphers.

Cryptographic hash functions (often called message digest functions) do not necessarily use keys, but are a related and important class of cryptographic algorithms. They take input data (often an entire message), and output a short fixed length hash, and do so as a one-way function. For good ones, ( 75 ) (two plaintexts which produce the same hash) are extremely difficult to find.

Message authentication codes (MACs) are much like cryptographic hash functions, except that a secret key is used to authenticate the hash value on receipt. These block an attack against plain hash functions.

(71)A.plaintext

B.ciphertext

C.data

D.hash

(72)A.stream cipher

B.hash function

C.Message authentication code

D.Block cipher

(73)A.of

B.for

C.with

D.in

(74)A.hash

B.stream

C.ciphertext

D.plaintext

(75)A.collisons

B.image

C.preimage

D.solution


相關推薦:2019年信息安全工程師上午真題及答案

在線題庫:信息安全工程師歷年真題自測估分

  • 本文標題: 2019年信息安全工程師上午基礎知識真題(八)
  • 本文鏈接:

近期直播

周默默

今日 20:00-21:00
消防沖刺學習方法及心態

一級消防工程師

進入課堂

徐子夫

今日 20:00-21:00
監理重點突破

監理工程師

進入課堂

孫璨

今日 20:00-21:00
一小時拿下教資22分

幼兒教師資格證

進入課堂

陳麗

10-21 19:30-21:30
初級銀行從業《個人貸款》考前押題

銀行業專業實務(個人貸款)

立即預約

周默默

10-23 20:00-21:00
二建考試介紹與備考建議

二級建造師

立即預約

劉豫婷

10-23 20:00-21:00
2019年10月初級銀行從業資格證考試之個人理財及基礎知識考試介紹

銀行業專業實務(個人理財)

立即預約

周默默

10-24 20:00-21:00
消防考試介紹及學習方法

一級消防工程師

立即預約

徐子夫

10-24 20:00-21:00
監理重點突破

監理工程師

立即預約

希賽小龍女

10-24 20:00-21:00
PMP?輕松備考三步走

PMP

立即預約

距離2020-05-23 考試還有

  • 2
  • 1
  • 9

題庫

程序員
電子商務設計師
政策法規
考試大綱
考試報名
歷年試題
信息安全工程師
軟件評測師
系統規劃與管理師
軟件設計師
嵌入式系統設計師
軟考英語
數據庫系統工程師
網絡工程師
網絡管理員
網絡規劃設計師
系統分析師
系統集成項目管理工程師
系統架構設計師
信息處理技術員
信息系統管理工程師
信息系統監理師
信息系統項目管理師
信息系統運行管理員