Asymmetric Encryption

ElGamal

is based on a discrete logarithm problem. It was described by Taher Elgamal in 1984. Also Extends Diffie-Hellman for use in encryption and digital signatures.

RSA

is based on factoring large numbers into their prime values. It was developed by Rivest, Shamir, and Adleman in 1977. 1) Is based on the difficulty of factoring N, a product of two large prime numbers (201 digits). 1) Has key-length ranges from about 512 bits to 8,000 bits (2401 digits). Rivest, Shamir Adleman

Elliptic curve cryptography or (ECC)

is based on groups of numbers in an elliptical curve. The use of elliptic curves in cryptography was suggested independently by Neal Koblitz and Victor S. Miller in 1985.

Merkle-Hellman (MH) Knapsack

is based on the subset sum problem: given a list of numbers and a sum, determine the subset used to create the sum. It was one of the earliest public key cryptosystems, invented by Ralph Merkle and Martin Hellman in 1978

Digital signing

is use to confirm the integrity of the message and the authenticity of a sender.

key space

starts around 1,000 bits and goes as high as 32,000 bits.

hybrid cryptography system

system combines the strengths of both the symmetric and asymmetric cryptography systems (i.e. symmetric systems can process large amounts of data relatively fast, and asymmetric systems can securely distribute keys).

Key exchange

to ensure keys are secure during transit. Asymmetric encryption is often used to securely exchange symmetric keys.

private key

type of key that is kept secret

Keyspace

typically starts around 1,000 bits and goes as high as 32,000 bits.

public key

a key that is made available to anyone

Asymmetric cryptography

a type of cryptography that is scalable for use in very large, expanding environments where data is frequently exchanged between different communication partners. 2n (2 keys per user).

Asymmetric encryption

also known as public key encryption, uses two keys that are mathematically related. Both keys together are called the key pair. Consider the following asymmetric encryption facts

asymmetric cryptographic system

are based on a trapdoor function creating a value that is easy to produce in one direction but difficult to reverse

Ephemeral keys

are generated every time the key establishment process is executed and only exist for the lifetime of a specific communication session. As such, these keys have a relatively short lifespan.

Radom Public Key

are generated for each session. No deterministic algorithm is used when generating the public keys.

Asymmetric key ciphers

are two associated algorithms that are inverses of each other. Both of the two algorithms are easy to compute.

Perfect forward secrecy

can be implemented in public-key cryptography system such that

Static keys

can be reused by multiple communication sessions. As such, these keys remain in use for a relatively long period of time

o Static keys

can be reused by multiple communication sessions. As such, these keys remain in use for a relatively long period of time

Asymmetric key encryption

can provide confidentiality (encryption), strong authentication, and non-repudiation