ENCRYPTION• Encryption is theprocess of transforminginformation to make itunreadable to anyoneexcept those possessingspecial knowledge,usually referred to as akey.• Encryption is theconversion of data intoa form, called a ciphertext that cannot beeasily understood byunauthorized people.
DECRYPTIONDecryption is the process of converting encrypteddata back into its original form, so it can beunderstood.
ENCRYPTIONEncryption/Decryption is a good idea when carryingout any kind of sensitive transaction, such as acredit-card purchase online, or the discussion of acompany secret between different departments inthe organization
SYMMETRIC KEY ENCRYPTIONSymmetric-key algorithms are a class of algorithmsfor cryptography that use trivially related, oftenidentical, cryptographic keys for both decryption andencryption.The keys, in practice, represent a shared secretbetween two or more parties that can be used tomaintain a private information link.
Public Key EncryptionSolves symmetric key encryption problem of having toexchangesecret key• Uses two mathematically related digital keys – publickey (widelydisseminated) and private key (kept secret by owner)• Both keys used to encrypt and decrypt message• Once key used to encrypt message, same key cannotbe used todecrypt message• For example, sender uses recipient’s public key toencrypt message;recipient uses his/her private key to decrypt it
Securing Channels of CommunicationSecure Sockets Layer (SSL):– Most common form of securing channels of communication; used toestablish a secure negotiated session (client-server session in whichURL of requested document, along with contents, is encrypted)S-HTTP:– Alternative method; provides a secure message-orientedcommunications protocol designed for use in conjunction withHTTPVirtual Private Networks (VPNs):– Allow remote users to securely access internal networks via theInternet, using Point-to-Point Tunneling Protocol (PPTP)
Secure Sockets Layer (SSL):Secure Sockets Layer, a protocol developed byNetscape for transmitting private documents via theInternet. SSL uses a cryptographic system that usestwo keys to encrypt data - a public key known toeveryone and a private or secret key known only tothe recipient of the message..
Virtual Private Networks (VPNs):A virtual private network (VPN) is a secure way ofconnecting to a private Local Area Network at aremote location, using the Internet or any unsecurepublic network to transport the network datapackets privately, using encryption. The VPN usesauthentication to deny access to unauthorizedusers, and encryption to prevent unauthorized usersfrom reading the private network packets.
S-HTTPAnother protocol for transmitting data securely overthe World Wide Web is Secure HTTP (S-HTTP). S-HTTP is designed to transmit individual messagessecurely.
FirewallsA firewall is a device or set of devices designed to permit ordeny network transmissions based upon a set of rules and isfrequently used to protect networks from unauthorizedaccess while permitting legitimate communications to pass.
AntivirusEasiest and leastexpensive way toprevent threats tosystem integrity.Antivirus software isused toprevent, detect, andremovemalware, including butnot limited to computerviruses, computerworm, Trojanhorses, spyware andadware.
PROXYIt is a computersystem or routerthat breaks theconnectionbetween senderand receiver