Core Cryptography Concepts

Posted by in Security+ | 0 comments

Many Security+ exam questions (and other security certification questions) require you to have a basic understanding of core cryptography concepts.

While these concepts have a lot of depth, the following bullets from the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide summarize the important concepts.

Get Certified Get Ahead

  • Integrity provides assurances that data has not been modified. Hashing ensures that data has retained integrity.
  • A hash is a number derived from performing a calculation on data, such as a message, patch, or update file.
  • Hashing creates a fixed-size string of bits or hexadecimal characters, which cannot be reversed to re-create the original data.
  • Common hashing algorithms include MD5 and Secure Hash Algorithm (SHA).
  • Confidentiality ensures that data is only viewable by authorized users. Encryption protects the confidentiality of data.
  • Encryption scrambles, or ciphers, data to make it unreadable if intercepted. Encryption normally includes an algorithm and a key.
  • Symmetric encryption uses the same key to encrypt and decrypt data.
  • Asymmetric encryption uses two keys (public and private) created as a matched pair.
    • Anything encrypted with the public key can only be decrypted with the matching private key.
    • Anything encrypted with the private key can only be decrypted with the matching public key.
  • Stream ciphers encrypt data one bit at a time. Block ciphers encrypt data in blocks.
  • Steganography provides a level of confidentiality by hiding data within other files. For example, it’s possible to embed data within the white space of a picture file.
  • Authentication validates an identity.
  • Non-repudiation prevents a party from denying an action.
  • Digital signatures provide authentication, non-repudiation, and integrity.
  • Users sign emails with a digital signature, which is a hash of an email message encrypted with the sender’s private key.
  • Only the sender’s public key can decrypt the hash, providing verification it was encrypted with the sender’s private key.

 

If you understand these concepts, you’ll find that they go a long way in helping you to correctly interpret Security+ questions.


 

If you’re looking to improve your understanding of the CompTIA Security+ concepts, check out the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide.

CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide

Leave a Comment

CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide

Subscribe To Our Newsletter

Join our mailing list and get a free excerpt of the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide.  This excerpt includes the introduction and Chapter 1.

You have Successfully Subscribed!

Get Certified Get Ahead is a participant in the Amazon Services LLC Associates Program,
an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.

Copyright © 2015 Get Certified Get Ahead. All Rights Reserved.