Safe prime: Difference between revisions

Revision as of 22:14, 21 April 2009

This article defines a property that can be evaluated for a prime number. In other words, every prime number either satisfies this property or does not satisfy this property.
View other properties of prime numbers | View other properties of natural numbers

Definition

A prime number $p$ is termed a safe prime if $p$ is odd and $(p-1)/2$ is also a prime number.

The corresponding prime $(p-1)/2$ is termed a Sophie Germain prime.

Relation with other properties

Related properties of primes or pairs of primes

Sophie Germain prime is a prime $q$ such that $2q+1$ is also a prime.
Twin primes are primes that differ by two.

Related properties of longer chains of primes

Cunningham chain of the first kind is a chain of primes $q_{1}<q_{2}<\dots <q_{k}$ such that $q_{i+1}=2q_{i}+1$ .
Bitwin chain is a collection of multiple pairs of twin primes, each pair being double the previous one.

Facts

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 ===Related properties of longer chains of primes===
-* [[Cunningham chain]] is a chain of primes <math>q_1 < q_2 < \dots < q_k</math> such that <math>q_{i+1} = 2q_i + 1</math>.
+* [[Cunningham chain of the first kind]] is a chain of primes <math>q_1 < q_2 < \dots < q_k</math> such that <math>q_{i+1} = 2q_i + 1</math>.
 * [[Bitwin chain]] is a collection of multiple pairs of twin primes, each pair being double the previous one.