S

SAM

See Security Accounts Manager.

sandbox

A set of rules that are used when creating a Java applet that prevents certain functions when the applet is sent as part of a web page.

scanning

The process that attackers use to gather information about how your network is configured.

screened host

A router that is in front of a server on the private network. Typically, this servers does packet filtering before reaching the firewall/proxy server that services the internal network.

secret key

See private key.

Secure Electronic Transaction (SET)

A protocol developed by Visa and MasterCard for secure credit card transactions. The protocol is becoming an accepted standard by many companies. SET provides encrypted credit card numbers over the Internet, and it is most suited to small amounts of data transmission.

Secure Hash Algorithm (SHA)

A one-way hash algorithm designed to ensure the integrity of a message.

Secure Hypertext Transfer Protocol (S-HTTP)

A protocol used for secure communications between a web server and a web browser.

Secure Shell (SSH)

A replacement for rlogin in Unix/Linux that includes security. rlogin allowed one host to establish a connection with another with no real security being employed, and SSH replaces this with slogin and digital certificates.

Secure Socket Layer (SSL)

A protocol that secures messages by operating between the Application layer (HTTP) and the Transport layer.

Secure WLAN Protocol (SWP)

A method of securing wireless networks that is beginning to gain momentum and acceptance.

Security Accounts Manager (SAM)

A database within Windows NT that contains information about all users and groups and their associated rights and settings within a Windows NT domain.

security audit

An audit of the system (host, network, etc.) for security vulnerabilities and holes.

security log

A log file used in Windows NT to keep track of security events specified by the domain's Audit policy.

security policy

Rules set in place by a company to ensure the security of a network. This may include how often a password must be changed or how many characters a password should be.

security professionals

Individuals who make their living working with computer security.

security tokens

Pieces of data that contain the rights and access privileges of the token bearer as part of the token.

security zone

A method of isolating a system from other systems or networks.

segment

A unit of data transmission found at the Transport Layer of OSI.

sensor

A device that collects data from the data source and passes it on to the analyzer.

separation of duties

A set of policies that are designed to reduce the risk of fraud and prevent other losses in an organization.

sequence number

A number used to determine the order in which parts of a packet are to be reassembled after the packet has been split into sections.

Sequenced Packet eXchange (SPX)

A connection-oriented protocol that is part of the IPX protocol suite. It operates at the Transport layer of the OSI model. It initiates the connection between the sender and receiver, transmits the data, and then terminates the connection. See also Internet Packet eXchange, Open Systems Interconnect.

Serial Line Internet Protocol (SLIP)

An older protocol that was used in early remote access environments. SLIP was originally designed to connect Unix systems together in a dial-up environment, and it only supports serial communications.

server

A computer that provides resources to the clients on the network.

server and client configuration

A network in which the resources are located on a server for use by the clients.

server authentication

The process that requires the workstation to authenticate against the server.

service

Services add functionality to the network by providing resources or doing tasks for other computers. In Windows 9x, services include file and printer sharing for Microsoft or Novell networks.

service accounts

Accounts created on a server for users to perform special services, such as backup operators, account operators, and server operators.

Service Level Agreement (SLA)

An agreement that specifies performance requirements for a vendor. This agreement may use MTBF and MTTR as performance measures in the SLA.

service pack

Operating system updates from Microsoft.

session key

The agreed-upon (during connection) key used between a client and a server during a session. This key is generated by encrypting the server's digital ID (after validity has been established). The key pair is then used to encrypt and verify the session key that is passed back and forth between client and server during the length of the connection.

Session layer

The fifth layer of the OSI model. It determines how two computers establish, use, and end a session. Security authentication and network naming functions required for applications occur here. The Session layer establishes, maintains, and breaks dialogs between two stations. See also Open Systems Interconnect.

SHA

See Secure Hash Algorithm.

share-level security

In a network that uses share-level security, instead of assigning rights to network resources to users, passwords are assigned to individual files or other network resources (such as printers). These passwords are then given to all users that need access to these resources. All resources are visible from anywhere in the network, and any user who knows the password for a particular network resource can make changes to it.

S-HTTP

See Secure Hypertext Transfer Protocol.

Shielded Twisted Pair (STP)

Network cabling media that has a shield, similar to coax, wrapped over the wires.

signal

Transmission from one PC to another. This could be a notification to start a session or end a session.

signal encoding

The process whereby a protocol at the Physical layer receives information from the upper layers and translates all the data into signals that can be transmitted on a transmission medium.

signaling method

The process of transmitting data across the medium. Two types of signaling are digital and analog.

signed applets

An applet that does not run in the Java sandbox and has higher system access capabilities. Signed applets are not usually downloaded from the Internet, but are usually provided by in-house or custom programming efforts.

Simple Mail Transfer Protocol (SMTP)

A protocol for sending e-mail between SMTP servers.

Simple Network Management Protocol (SNMP)

The management protocol created for sending information about the health of the network to network management consoles.

Single Loss Expectancy (SLE)

The cost of a single loss when it occurs. This loss can be a critical failure, or it can be the result of an attack.

single sign-on

A relationship between the client and the network wherein the client is allowed to log on one time, and all resource access is based upon that logon (as opposed to needing to log on to each individual server to access the resources there).

site survey

Listening in on an existing wireless network using commercially available technologies.

six-cartridge backup

A type of backup tape rotation that mixes onsite and offsite copies.

skipjack

An encryption algorithm developed as a possible replacement for Data Encryption Standard (DES) that is classified by the National Security Agency (NSA). Not much is known about this encryption algorithm except that it uses an 80-bit key.

SLIP

See Serial Line Internet Protocol.

SMTP

See Simple Mail Transfer Protocol.

SMTP relay

A feature designed into many e-mail servers that allows them to forward e-mail to other e-mail servers.

smurf attack

An attack caused by pinging a broadcast to a number of sites with a false "from" address. When the hosts all respond to the ping, they are flooding the false "from" site with echoes.

snapshot backup

A method of performing backups that creates a compressed file of a database as it exists at this moment without taking the users offline. A snapshot backup can take the place of other backups. It is often run on mirrored servers, but the snapshot captures only the most recent version of files.

sniffer

A physical device that listens in (sniffs) on network traffic and looks for items it can make sense of. There is a legitimate purpose for these devices because they are used to analyze traffic by administrators. However, when they are used by sources other than the administrator, they become security risks.

sniffing

Sniffing is also known as wiretapping, eavesdropping, and a number of other terms (packet sniffing, network sniffing, etc.).

SNMP

See Simple Network Management Protocol.

snooping

Looking through files in hopes of finding something interesting.

social engineering

Attacks that use others by deceiving them. For example, you could call a busy receptionist and tell her that you are a company salesman who is stranded at a customer's site. You are trying to do a demo, but you cannot get your password to work. Can she tell you her password just so you can get the demo going and not lose the account?

software exploitation

Attacks launched against applications and higher-level services.

sockets

The primary method used to communicate with services and applications such as WWW and Telnet.

spam

Unwanted, unsolicited e-mail sent in bulk.

spikes

Momentary or instantaneous increases in a power line.

spoofing attack

An attempt by someone or something to masquerade as someone else.

SPX

See Sequenced Packet eXchange.

SSH

See Secure Shell.

SSL

See Secure Socket Layer.

state table

A firewall security method that monitors the status of all the connections through the firewall.

stateful packet filtering

Inspections that occur at all levels of the network and provide additional security using a state table that tracks every communications channel.

static ARP table entry

An entry in the ARP table that is manually added by a user when a PC will be accessed often. This will speed up the process of communicating with the PC because the IP-to-MAC address will not have to be resolved.

static routing

A method of routing packets where the router's routing table is updated manually by the network administrator instead of automatically by a route discovery protocol.

stealth ports

Ports that are open but may not be obvious (invisible to those who do not know they exist). They are often exploited by Trojan horses.

stealth virus

A virus that will attempt to avoid detection by masking itself from applications.

steganography

The science of hiding information within other information, such as a picture.

strength

The effectiveness of a cryptographic system in preventing unauthorized decryption.

subscriber

The individual who is attempting to present the certificate proving authenticity.

surge protectors

Devices that protect electrical components from momentary or instantaneous increases (called spikes) in a power line.

switched

A network that has multiple routes to get from a source to a destination. This allows for higher speeds.

SWP

See Secure WLAN Protocol.

symmetrical keys

The keys that are used when the same key is used to encrypt and decrypt data.

SYN flood

A Denial of Service attack in which the hacker sends a barrage of SYN packets. The receiving station tries to respond to each SYN request for a connection, thereby tying up all the resources. All incoming connections are rejected until all current connections can be established.

system architecture

Documents that provide you with the blueprint of your organization's software and hardware infrastructure.