Internet Security
- 1. Internet Security Prepared By : 1. Anany Munshi - 17IT443 2. Jainam Parikh - 17IT467 Guided By : Prof. Mohan .M. Khambalkar
- 2. Introduction Security of the data being transmitted. Protecting the data from interception and protecting the sending and receiving parties from unwanted threats such as viruses and spam. Wireless systems are also very vulnerable to hacker attacks simply because radio waves are easily picked up and used by anyone with an appropriate receiver.
- 3. Types of Security Threats 1. Viruses A virus is a small program designed to implement some nefarious action in a computer. A virus typically rides along with some other piece of information or program so that it can be surreptitiously inserted into the computer’s hard drive or RAM. Viruses typically interfere with the operating system, causing it to do unwanted things or not to perform certain functions. Computer viruses are designed to spread themselves within the computer or to be retransmitted to others in e-mails. These viruses are called worms as they automatically duplicate and transmit themselves from network to network and computer to computer.
- 4. 2. Spam A more recent threat, while not actually damaging, is unwanted ads and solicitations via email called spam. Spam clogs up the email system with huge quantities of unwanted data and uses transmission time and bandwidth that could be used in a more productive way. Spam is not illegal, but you must remove the spam yourself. 3. Spyware Spyware is a kind of software that monitors a computer and its user while he or she accesses the Internet or email. It then collects data about how that user uses the Internet such as Internet website access, shopping, etc. Some examples of dangerous practices are the capture of credit card numbers, delivery of unsolicited pop-up ads, and capture of Web-browsing activity.
- 5. 4. Denial-of-Services (DOS) This is a process that transmits errors in the communications protocol and causes the computer to crash or hang up. This type of vandalism doesn’t steal information, but it does prevent the user from accessing the operating system, programs, data files, applications programs, or communications links. One special type of DoS attack is called Smurfing. A smurf attack usually overwhelms ISP servers with a huge number of worthless packets, thereby preventing other ISP subscribers from using the system.
- 6. Security Measures 1. Encryption and Decryption Encryption involves converting a message to some other form that makes it useless to the reader. Decryption is the reverse process that translates the encrypted message back to readable form.
- 7. Two basic types of encryption: 1. Secret key encryption (SKE) or Private key encryption Here, both sending and receiving parties must have the same key. The problem with this method lies in sharing the key. How do you transmit or distribute the secret key in a secure manner? 2. Public key encryption (PKE) It uses two keys, a public key and a private key, in the encryption process. The public key can be openly shared in public. In fact, the public key is sent by the receiver to the transmitting party, and it is used in the encryption process. A secret key is also needed in the decryption process.
- 8. Types of encryption methods: 1. Data Encryption Standard (DES) DES uses a 56-bit key for encryption. The key is actually 64 bits or 8 bytes long, where 1 bit of each byte is a parity bit. The remaining eight 7-bit bytes make up the key. The plaintext is encoded or encrypted in 64-bit blocks. DES was found to be insufficiently secure as the key could actually be discovered by a very fast computer, simply by trying all the related key combinations. This led to the development of 3DES (pronounced triple-dez), which puts the plaintext through three separate sequential DES encryptions, creating a virtually unbreakable code. 1. Advanced Encryption Standard (AES) It uses 128-, 192-, or 256-bit keys, making it ultra secure and essentially impossible to break.
- 9. How Public Key Encryption is used (PKE): 1. Two parties X and Y wish to communicate. Party X will transmit information to Y. 2. Both X and Y have encryption software that generates both public and private keys. 3. The receiving party Y first transmits the public key to X. This can be done by using non secure or unencrypted methods. 4. The transmitting party X then uses the public key to encrypt the message that is sent to Y. 5. Then Y decrypts the message by applying the private key that matches the public key.
- 10. 2. Authentication Authentication is the process of verifying that you are who you say you are. Authentication ensures that the transmitting and receiving parties are really who they say they are and that their identities have not been stolen or simulated. The most common methods of authentication are the use of passwords or personal identification numbers (PIN). Common biometric ID methods are fingerprint scans, retinal eye scans, voiceprints, or video facial recognition.
- 11. 3. Secure Socket Layer (SSL) The processes of encryption/decryption and authentication are used together to ensure secure transactions over the Internet. All these processes are combined into a protocol known as the Secure Socket Layer (SSL).
- 12. How SSL Works: 1. Server X transmits its public key to client X. It is signed by a digital signature as described earlier. 2. The client then generates a secret key. 3. Client X uses the public key to encrypt the secret key, which is sent to server Y. 4. Client X encrypts the message, using private key encryption methods, and sends the message to server Y. 5. Server Y decrypts the private key previously sent and then uses it to decrypt the message. 6. Hashing and digital signatures are used throughout the process to ensure identity.
- 13. 5. Firewalls A firewall is a piece of software that monitors transmissions on a network and inspects the incoming information to see if it conforms to a set of guidelines established by the software or the organization or person owning the network. It examines TCP/IP packets and acts as a filter to block access from inputs that do not match a set of rules set up in the firewall. Some operating systems such as Microsoft Windows now come with a built-in firewall.
- 14. 6. Antivirus, Antispam, and Antispyware Software The antivirus and antispyware programs scan all files on the hard drive either automatically or on command, to look for viruses. The antivirus software looks for a pattern of code unique to each virus, and when it is identified, the software can remove the virus or in some cases quarantine and isolate the infected file so that it does no harm. Anti spyware works the same way by scanning all files, searching for patterns that designate a spyware program. It then removes the program.
- 15. 7. Virtual Private Network (VPN) A Virtual Private Network (VPN) is a network that is constructed using public wires, usually the internet, to connect remote users or regional offices to a company’s private, internal network. VPNs use one of two special protocols for the encapsulation and encryption process. 1. IPsec (Internet Protocol security) ● IPsec encrypts the data along with the TCP header and then adds another header that identifies the kind of encryption used plus a trailer that contains the authentication. ● An IP header is added to form the datagram or packet to be transmitted. ● Next, this datagram is encrypted and encapsulated in one additional IP datagram, which is also encrypted. ● The combined packet is transmitted. This process is referred to as tunneling.