security

security

In finance, written evidence of ownership conferring the right to receive property not currently in the holder's possession. The most common securities are stocks and bonds. Governments, companies, and financial institutions use securities to raise money. Stocks are securities issued in the form of equity ownership. Bonds are securities that take the form of debt. They constitute promises to pay a specified amount at a specified date and to pay interest at a specified rate in the interim. Most government securities are bonds that pay a fixed amount of interest per year; unlike commercial securities, their repayment is guaranteed. Both stocks and bonds are traded publicly on organized exchanges such as the New York Stock Exchange, the London Stock Exchange, and the Tokyo Stock Exchange. External forces such as international troubles, changes in government policies, and trends in foreign stock markets all have an effect on security prices. For individual stocks, the company's current and prospective financial performance play an important role, as do overall trends within its business sector. See also investment; saving.

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security

See computer security and information security.

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security

1. something given or pledged to secure the fulfilment of a promise or obligation

2. a person who undertakes to fulfil another person's obligation

3. the protection of data to ensure that only authorized personnel have access to computer files

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(security)

security - Protection against unauthorized access to, or alteration of, information and system resources including CPUs, storage devices and programs. Security includes: * confidentiality - preventing unauthorized access; integrity - preventing or detecting unauthorized modification of information. * authentication - determining whether a user is who they claim to be. * access control - ensuring that users can access the resources, and only the resources, that they are authorised to. * nonrepudiation - proof that a message came from a certain source. * availability - ensuring that a system is operational and accessible to authorised users despite hardware or software failures or attack. * privacy - allowing people to know and control how information is collected about them and how it is used. Security can also be considered in the following terms: * physical security - who can touch the system to operate or modify it, protection against the physical environment - heat, earthquake, etc. * operational/procedural security - who is authorised to do or responsible for doing what and when, who can authorise others to do what and who has to report what to who. * personnel security - hiring employees, background screening, training, security briefings, monitoring and handling departures. * System security - User access and authentication controls, assignment of privilege, maintaining file and filesystem integrity, backup, monitoring processes, log-keeping, and auditing. * network security - protecting network and telecommunications equipment, protecting network servers and transmissions, combatting eavesdropping, controlling access from untrusted networks, firewalls, and intrusion detection. Encryption is one important technique used to improve data security. OWASP is the free and open application security community.