| Lesson 7 | Applied encryption processes |
| Objective | Describe the application of encryption to security. |
Application of encryption to security
Most modern dynamic encryption uses a combination of symmetric encryption,asymmetric encryption and one-way encryption or hash encryption. This combination capitalizes on the strengths of each type of encryption, while minimizing their
weaknesses.
One-way encryption:
A type of encryption where information is encrypted once and cannot be decrypted. One-way encryption is typically used for creating message digests.
- Symmetric encryption : A type of encryption where the same key is used to encrypt and decrypt the message.
- Asymmetric encryption:A type of encryption that uses one key to encrypt a message and another to decrypt the message. (Also, public-key encryption)
- Hash algorithm: A numeric function which mixes the ordering of input values to hopefully get an even distribution. (Also, hash function)
Applied cryptography
Encryption techniques are used to achieve:
- Data confidentiality: by encryption and decryption
Encryption: The process of disguising a message to make it unreadable by humans. The resulting data is called ciphertext.
- Authentication: by using public-key encryption , certificates or digital signatures
Digital signature: A digital code that can be attached to an electronically transmitted message that uniquely identifies the sender.
Like a written signature, the purpose of a digital signature is to guarantee that the individual sending the message really is who he or she claims to be. Digital signatures are especially important for electronic commerce and are a key component of most authentication schemes.
- Data integrity: by using message digests or hash algorithms
- Hash algorithm: A numeric function which mixes the ordering of input values to hopefully get an even distribution. (Also, hash function)
- Nonrepudiation: using digital signatures
- Message digest: The representation of text in the form of a single string of digits, created using a formula called a one-way hash function. Encrypting a message digest with a private key creates a digital signature, which is an electronic means
of authentication.
- Public-key encryption: A cryptographic system that uses two keys a public key known to everyone and a private or secret key known only to the recipient of the message.
- Certificate: An attachment to an electronic message used for security purposes.
A digital certificate is commonly used to verify that a user sending a message is who he or she claims to be, and to provide the receiver with the means to encode a reply.
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Digital signature: A digital code that can be attached to an electronically transmitted message that uniquely identifies the sender.
Like a written signature, the purpose of a digital signature is to guarantee that the individual sending the message really is who he or she claims to be. Digital signatures are especially important for electronic commerce and are a key component of most
authentication schemes.
Encryption protocols
Programs such as IIS, Netscape Suite Spot, Pretty Good Privacy (PGP), Exchange Server, and Windows NT, as well as protocols such asSecure Multipurpose Internet Mail Extension (S/MIME) and
Secure Sockets Layer (SSL) all employ a combination of symmetric, asymmetric and hash encryption. Methods such as Virtual Private Networks (VPNs) and protocols such as Secure HTTP (SHTTP) also use such combinations.
- Secure Multipurpose Internet Mail Extension (S/MIME): A specification for secure electronic mail. S/MIME was designed to add security to e-mail messages in MIME format.
The security services offered are authentication (using digital signatures) and privacy (using encryption).
- Secure Sockets Layer (SSL): A technology embedded in Web servers and browsers that encrypts traffic.
- Virtual Private Network (VPN): An extended local area network (LAN) that enables an organization to conduct secure, real-time communication.
- Secure HTTP (SHTTP): A form of encryption that takes place at the hypertext markup language level. This allows a Web browser to transfer sensitive information across the Internet.
Encryption authentication processes
Firewall Strategies - Exercise