PKI (Public Key Infrastructure): A system of digital certificates, Certificate Authorities, and other registration authorities that verify the validity of each party involved in an internet transaction. The intent is to establish a trusted relationship between the parties. PKI is necessary and foundational for certificate-based Virtual Private Networks.
Probe: A type of hacking attempt characterized by repetitious, sequential access attempts. For example, a hacker might try to probe a series of ports in search of one that is open, or one might probe a range of IP addresses in search of a responsive computer.
Public key cryptography: Cryptography in which a public and private key pair is used, encrypting the data at the sender’s end and decrypting it at the receiver’s end. Because the data are encrypted while they travel the public internet, no additional security is needed—the data can safely use public networks without loss of confidentiality.
Session hijacking: An intrusion technique whereby a hacker sends a command to an already existing connection between two machines, in order to wrest control of the connection away from the machine that initiated it. The hacker’s goal is to gain access to a server while bypassing normal authentication measures.
Session key: The secret (symmetric) key used to encrypt each set of data on a transaction basis. A different session key is used for each communication session.
Social engineering attack: An attack that does not depend on technology as much as it depends upon tricking or persuading an individual to divulge privileged information to the attacker, usually unknowingly.
Spoofing: Altering data packets to falsely identify the originating computer. Spoofing is generally used when a hacker wants to make it difficult to trace where the attacks are coming from.
SSID (Service Set Identifier): A unique string, up to 32 characters, that serves as the name of a wireless local area network (WLAN). Because a SSID differentiates one network from another, multiple wireless networks can function even when their ranges overlap. In an open network, the access point broadcasts the SSID. You can configure your wireless access point (WAP) not to broadcast the SSID, so that users trying to join the network must already know the network name.
SSL (Secure Sockets Layer): A protocol for transmitting private documents over the internet, often used by eCommerce sites (among others). SSL works by using a private key to encrypt data transferred over an SSL connection.
Triple-DES (3DES): A cryptographic algorithm using three keys (rather than one or two). Triple DES is simply another mode of DES operation, where the DES algorithm is applied three times on the data to be encrypted, using a different key each time.
Tunnel: In Virtual Private Networks, an encrypted connection between sites. Only the originator and the receiver of the message see it in its clear state. Any hacker trying to intercept the message en route gets nothing but a scrambled mess. Because the path of a VPN message has “light” (clear text) at each end but “darkness” (obscurity) at all the between-points, it is called, metaphorically, a VPN tunnel.
WPA (Wi-Fi Protected Access): A data encryption specification for 802.11 wireless networks. Wireless networks rely on radio waves, which broadcast in all directions. Any device within range of a wireless access point could eavesdrop upon its transmissions. WPA encrypts wireless data so that an eavesdropper intercepts gibberish, while authorized endpoints receive clear, decrypted data. WPA replaces WEP, a weaker wireless encryption standard that attackers can readily break.