patent - The sole right, granted by the government, to sell, use, and manufacture an invention or creation.

PKI - Public-Key Infrastructure. PKIs are designed to solve the key management problem. See also key management.

padding - extra bits concatenated with a key, password, or plaintext.

password - A character string used as a key to control access to files or encrypt them.

PKCS - Public-Key Cryptography Standards. A series of cryptographic standards dealing with public-key issues, published by RSA Laboratories.

plaintext - The data to be encrypted.

Pollard p-1 and Pollard p-2 methods - Algorithms that attempt to find a prime factor p of a number N by exploiting properties of p-1 and p+1. See also factoring, prime factor, prime number.

Pollard Rho method - A method for solving the discrete logarithm and elliptic curve discrete logarithm.

precomputation attack - An attack where the adversary precomputes a look-up table of values used to crack encryption or passwords. See also dictionary attack.

primality testing - A test that determines, with varying degree of probability, whether or not a particular number is prime.

prime factor - A prime number that is a factor of another number is called a prime factor of that number.

prime number - Any integer greater than 1 that is divisible only by 1 and itself.

privacy - The state or quality of being secluded from the view and or presence of others.

private exponent - The private key in the RSA public-key cryptosystem.

private key - In public-key cryptography, this key is the secret key. It is primarily used for decryption but is also used for encryption with digital signatures.

proactive security - A property of a cryptographic protocol or structure which minimizes potential security compromises by refreshing a shared key or secret.

probabilistic signature scheme (PSS) - A provably secure way of creating signatures using the RSA algorithm.

protocol - A series of steps that two or more parties agree upon to complete a task.

provably secure - A property of a digital signature scheme stating that it is provably secure if its security can be ties closely to that of the cryptosystem involved. See also digital signature scheme.

pseudorandom number - A number extracted from a pseudorandom sequence.

pseudorandom sequence - A deterministic function which produces a sequence of bits with qualities similar to that of a truly random sequence.

PSS - See probabilistic signature scheme.

public exponent - The public key in the RSA public-key cryptosystem.

public key - The public-key cryptography this key is make public to all, it is primarily used for encryption but can be used for verifying signatures.

public-key cryptography - Cryptography based on methods involving a public key and a private key.

quadratic sieve - A method of factoring an integer, developed by Carl Pomerance.

RSA algorithm - A public-key cryptosystem based on the factoring problem. RSA stands for Rivest, Shamir and Adleman, the developers of the RSA public-key cryptosystem and the founders of RSA Data Security, Inc.

random number - As opposed to a pseudorandom number, a truly random number is a number produced independently of its generating criteria. For cryptographic purposed, numbers based on physical measurements, such as a Geiger counter, are considered random.

reduced keyspace - When using an n bit key, some implementations may only use r <n bits of the key; the result is a smaller (reduced) key space.

relatively prime - Two integers are relatively prime if they have no common factors, e.g., (14, 25).

reverse engineer - To ascertain the functional basis of something by taking it apart and studying how it works.

rounds - The number of times a function, called a round function, is applied to a block in a Feistel cipher.