Browse Definitions :
Definition

# Mersenne prime (or Marsenne prime)

A Mersenne (also spelled Marsenne) prime is a specific type of prime number. It must be reducible to the form 2 n - 1, where n is a prime number. The term comes from the surname of a French monk who first defined it. The first few known values of n that produce Mersenne primes are where n = 2, n = 3, n = 5, n = 7, n = 13, n = 17, n = 19, n = 31, n = 61, and n = 89.

With the advent of computers to perform number-crunching tasks formerly done by humans, ever-larger Mersenne primes (and primes in general) have been found. The quest to find prime numbers is akin to other numerical searches done by computers. Examples are the decimal expansions of irrational numbers such as pi (the circumference-to-diameter ratio of a circle) or e (the natural logarithm base). But the 'next' prime is more difficult to find than the 'next' digit in the expansion of an irrational number.

It takes the most powerful computer a long time to check a large number to determine if it is prime, and an even longer time to determine if it is a Mersenne prime. For this reason, Mersenne primes are of particular interest to developers of strong encryption methods.

In August 2008, Edson Smith, a system administrator at UCLA, found the largest prime number known to that date. Smith had installed software for the Great Internet Mersenne Prime Search (Gimps), a volunteer-based distributed computing project.  The number (which is a Mersenne prime) is 12,978,189 digits long. It would take nearly two-and-a-half months to write out and, if printed, would stretch out for 30 miles.

This was last updated in March 2011
• OPSEC (operations security)

OPSEC (operations security) is a security and risk management process and strategy that classifies information, then determines ...

• smart contract

A smart contract is a decentralized application that executes business logic in response to events.

• compliance risk

Compliance risk is an organization's potential exposure to legal penalties, financial forfeiture and material loss, resulting ...

• threat modeling

Threat modeling is a procedure for optimizing application, system or business process security by identifying objectives and ...

• social engineering

Social engineering is an attack vector that relies heavily on human interaction and often involves manipulating people into ...

• distributed denial-of-service (DDoS) attack

A distributed denial-of-service (DDoS) attack is one in which multiple compromised computer systems attack a target, such as a ...

• change control

Change control is a systematic approach to managing all changes made to a product or system.

• disaster recovery (DR)

Disaster recovery (DR) is an organization's ability to respond to and recover from an event that affects business operations.

• risk mitigation

Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

• race condition

A race condition is an undesirable situation that occurs when a device or system attempts to perform two or more operations at ...

• storage security

Storage security is the group of parameters and settings that make storage resources available to authorized users and trusted ...

• cloud storage

Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, ...

Close