CSCU Module 04 Data Encryption.pdf

Data Encryption Module 4

Simplifying Security.

1

Copyright © by EC-Council All Rights Reserved. Reproduction is Strictly Prohibited.

May 23, 2011

40 Percent of IT Workers Could Hold Employer Networks Hostage, Survey Finds Roughly 40 percent of IT workers believe they could hold an employer’s network hostage — even after leaving the company — by withholding or hiding encryption keys, according to a recent survey of 500 IT security specialists. The study, released Monday, May 23, also revealed that a third of survey respondents were confident that their knowledge and access to encryption keys and certificates could bring a company to a halt with little effort. Conducted in April 2011, the survey was sanctioned by Venafi, a network key and encryption provider. “It’s a shame that so many people have been sold encryption but not the means or knowledge to manage it,” said Jeff Hudson, CEO of Venafi, in a statement. “IT departments must track where the keys are and monitor and manage who has access to them. ... It’s no longer rocket science. Yet recent, costly breaches at Sony, Epsilon and elsewhere reinforce the need for both more encryption and effective management.” http://www.govtech.com

2


Module Objectives Common Terminologies

Usage of Encryption

What Is Encryption?

Digital Certificates

Objectives of Encryption

Working of Digital Certificates

Types of Encryption

Digital Signature

Encryption Standards

How Digital Signature Works?

Symmetric vs. Asymmetric Encryption

Cryptography Tools

3


Module Flow

Encryption

Types of Encryption



Digital Signature

Cryptography Tools

4


Common Terminologies Plaintext Plaintext or cleartext is unencrypted readable text

Cipher Text Cipher text is encrypted and unreadable until it is decrypted to plaintext with a key

Encryption Key An encryption key is a piece of information that is used to encrypt and decrypt data

5


What Is Encryption? Encryption is the process of converting data into a cipher text that cannot be understood by the unauthorized people To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it Encryption is used to protect sensitive information during transmission and storage

Bob

Plain text (‘Morpheus’)

Encrypted DATA (‘3*.,~’@!w9”)

Encrypted DATA is received by Alice

6

Alice receives the plain data after decryption

Alice


Objectives of Encryption Data Integrity

Authentication

The receiver of a message can check whether the message was modified during transmission, either accidentally or deliberately

The receiver of a message can verify the origin of the message No other user should be able to send a message to the recipient as the original sender (data origin authentication)

Non‐repudiation

The sender of a message cannot deny that he/she has sent the message

7


Usage of Encryption It helps to safely store sensitive information on a computer or external storage media

Encryption is used to protect user credentials such as user name and passwords

Encryption provides a secure medium for users to connect to their friends’ or employees’ network from outside of the home or office

It provides a higher level of trust when receiving files from other users by ensuring that the source and contents of the message are trusted

It is also used as a resource for web‐based information exchange to protect important information such as credit card numbers

Encryption provides assurance of a sender’s identity

8


Module Flow

Encryption

Types of Encryption



Digital Signature

Cryptography Tools

9


Types of Encryption Symmetric Encryption

Symmetric Encryption

Encryption Dear John, This is my A/C number 7974392830

Symmetric encryption (secret‐key, shared‐key, and private‐key) uses the same key for encryption and decryption

Plain text

Decryption Guuihifhofn kbifkfnnfk Nklclmlm #^*&(*)_(_

Dear John, This is my A/C number 7974392830

Cipher text

Plain text

Asymmetric Encryption


Decryption

Encryption

Asymmetric encryption (public key) uses different encryption keys for encryption and decryption. These keys are known as public and private keys


Guuihifhofn kbifkfnnfk Nklclmlm #^*&(*)_(_

Plain text

Cipher text


Plain text

Hash function

Hash Function Hash function (message digests or one‐way encryption) uses no key for encryption and decryption

Hash function

Plain text

10

Cipher text


Symmetric vs. Asymmetric Encryption Symmetric Encryption


Symmetric encryption uses only one key for both encryption and decryption The key cannot be shared freely

Asymmetric Encryption uses a public key for encryption and a private key for decryption

Symmetric encryption requires that both the sender and the receiver know the secret key

In asymmetric encryption, the public key can be freely shared, which eliminates the risk of compromising the secret key

Using symmetric encryption, data can be encrypted faster

The encryption process using Asymmetric Encryption is slower and more complex

This algorithm is less complex and faster

Asymmetric encryption ensures confidentiality, integrity, authentication, and non‐repudiation

Symmetric encryption ensures confidentiality and integrity

11


Module Flow

Encryption

Types of Encryption



Digital Signature

Cryptography Tools

12



Data Encryption Standard (DES)

Advanced Encryption Standard (AES)

Data Encryption Standard (DES) is the name of the Federal information Processing Standard (FIPS) 46‐3, which describes the data encryption algorithm (DEA)

Advanced Encryption Standard (AES) is a symmetric‐key encryption standard adopted by the U.S. government

The DEA is a symmetric cryptosystem originally designed for implementation in hardware

It has a 128‐bit block size, with key sizes of 128, 192 and 256 bits, respectively, for AES‐128, AES‐192 and AES‐256

DEA is also used for single‐user encryption, such as to store files on a hard disk in encrypted form

13


Module Flow

Encryption

Types of Encryption



Digital Signature

Cryptography Tools

14


Digital Certificates A digital certificate is an electronic card that provides credential information while performing online transactions It acts as an electronic counterpart to a drivers license, passport, or membership card and verifies the identity of all users involved in online transactions A digital certificate generally contains: Details of owner’s public key

Owner’s name

Digital signature of the CA (issuer)

Expiration date of public key

Name of the Certificate Authority (CA) who issued the digital certificate

Serial number of digital signature

15


How Digital Certificates Work Certification Authority (CA)

Validation Authority (VA)

Updates Information

Request for Issuing Certificate

Public Key Certificate

Public Key Certificate

Registration Authority (RA)

Determined Result

User Applies for Certificate

User

Message in public key certificate signed with digital signature

Public Key

 Validation of electronic signature

Private Key

 Inquires about public key certificate validity to validation authority

16


Module Flow

Encryption

Types of Encryption



Digital Signature

Cryptography Tools

17


Digital Signature Digital signature implements asymmetric cryptography to simulate the security properties of a signature in digital, rather than written form

Digital signature schemes involve two encryption keys: a private key for signing the message and a public key for verifying signatures

Digital standards follow the open standards as they are not tied to an individual or manufacturer

It is often used to implement electronic signatures and can be used by any type of message

It is independent of the signature verification between the sender and the receiver

18


How Digital Signature Works SIGN

Confidential Information

Hash value

ACCEPT

Append the signed hash code to message

Sender signs hash code using his PRIVATE key

SEAL

Encrypt message using one‐time symmetric key

OPEN

Encrypt the symmetric key using recipient’s PUBLIC key

Decrypt message using one‐time symmetric key

Recipient decrypt one‐time symmetric key using his PRIVATE key

VERIFY

DELIVER

Mail electronic envelopes to the recipient

Unlock the hash value using sender’s PUBLIC key

19

Rehash the message and compare it with the hash value attached with the mail


Module Flow

Encryption

Types of Encryption



Digital Signature

Cryptography Tools

20


Cryptography Tool: TrueCrypt TrueCrypt creates a virtual encrypted disk within a file and mounts it as a real disk Encrypts an entire partition or storage device such as USB flash drive or hard drive Encrypts a partition or drive where Windows is installed (pre‐boot authentication) Encryption is automatic, real‐time (on‐the‐fly), and transparent

http://www.truecrypt.org

21


Cryptography Tools Folder Lock

PixelCryptor

http://www.newsoftwares.net

http://www.codegazer.com

AxCrypt

EncryptOnClick

http://www.axantum.com

http://www.2brightsparks.com

Cryptainer LE

SafeHouse Explorer

http://www.cypherix.co.uk

http://www.safehousesoftware.com

Advanced Encryption Package

Kruptos 2 Professional

http://www.intercrypto.com

http://www.kruptos2.co.uk

22


Module Summary  Encryption is the process of converting data into a cipher text that cannot be understood by the unauthorized people  Symmetric encryption uses only one key for both encryption and decryption, whereas asymmetric encryption uses a public key for encryption and a private key for decryption  Encryption provides a higher level of trust when receiving files from other users by ensuring that the source and contents of the message are trusted  A digital certificate is an electronic card that provides credential information when performing online transactions  A digital signature implements asymmetric cryptography to simulate the security properties of a signature in digital, rather than written form

23


CSCU Module 04 Data Encryption.pdf

Recommend Documents