Application of Cryptography

Question 1

Uses for cryptography

Answer 1

The settings where encryption is often used are:
- Files and directories
- Entire disks and volumes
- E-mail
- Web browsing
- Web services
- Remote network access

Question 2

File Encryption

Answer 2

Encryption is one form of access control that can be used to determine who is permitted to access files. When a file—even when it is present on a public file server— is encrypted, only individuals who possess the encryption key can access its contents. File encryption can also be used to protect the contents of a file when it is transmitted over a public network by e-mail or FTP.

Tools used to encrypt files and directories include:
- EFS Encryption File System
- PCP Pretty Good Privacy
- GPG Gnu Privacy Guard
- WInZip
- Crypt

Question 3

Disk Encryption

Answer 3

An entire hard disk or volume (a logical subset of a hard disk) can be
encrypted. Tools available for encrypting an entire volume include:
- PGP
- S/Mime
- PEM Privacy-Enhanced Mail
- MOSS

Question 4

Secure Point-to-Point communcations

Answer 4

Encryption can be used to protect communications between any two systems—two servers, two workstations, or a workstation and a server, for instance. Some of the technologies available are:
- SSH Secure Shell
- IPsec
- SSL/TLS Secure Socket layer / Transport layer Security

Question 5

Web Browser Security

Answer 5

Web browsers are client programs that access web-based applications in an organization or across the Internet. Web browsers communicate with web servers using the HyperText Transfer Protocol (HTTP) in either a secured or non-secured mode.

Question 6

Web Services Security

Answer 6

Web services is the name for machine-to-machine communications that can take place within a distributed application or a client-server application. Web
services are built upon the same HTTP/HTTPS protocols used by web browsers, but structured for non-interactive communications.
In e-commerce applications (that is, any web-based application in which sensitive information is displayed or exchanged such as banking, credit card, and personal information such as address, social security, and other identifying numbers), most or all data transmitted between the application and the user’s browser will be encrypted.

Question 7

VPN

Answer 7

A virtual private network (VPN) is a logical network connection between two points. All network traffic in a VPN connection is encapsulated in a “tunnel,” and the traffic is usually (but not necessarily) encrypted, thereby protecting the contents of the traffic from disclosure to eavesdroppers.