Logical Security consists of software safeguards for an organization’s systems, including user identification and password access, authentication, access rights and authority levels. These measures are to ensure that only authorized users are able to perform actions or access information in a network or a workstation. It is a subset of computer security.

Logical Security is also the name of the company started by Certified Information Systems Security Professional (CISSP) trainer and author Shon Harris.

Elements of logical security include:

Token Authentication comprises security tokens which are small devices that authorized users of computer systems or networks carry to assist in identitfying that who is logging in to a computer or network system is actually authorized. They can also store cryptographic keys and biometric data. The most popular type of security token (RSA’s SecurID) displays a number which changes every minute. Users are authenticated by entering a personal identification number and the number on the token. The token contains a time of day clock and a unique seed value, and the number displayed is a cryptographic hash of the seed value and the time of day. The computer which is being accessed also contains the same algorithm and is able to match the number by matching the user’s seed and time of day. Clock error is taken into account, and values a few minutes off are sometimes accepted. Another similar type of token (CRYPTOCard) can produce a value each time a button is pressed. Other security tokens can connect directly to the computer through USB, Smart card or Bluetooth ports, or through special purpose interfaces. Cell phones and PDA's can also be used as security tokens with proper programming.