If you are new to my Cryptology Series or are having trouble with any of the terminology, I encourage you to go to my blog and check out parts 1,2,3,4 and 5. I will link to the other parts of the series at the bottom of this post. Now let's get started!

In Cryptology Series Parts 4 & 5 we discussed the two main methods of encryption systems, symmetric and asymmetric systems.

Symmetric Cryptography

Uses symmetric keys known as secret keys, sender and receiver use two instances of the same key
Benefit: much faster and less computationally intensive
Weakness: Secure key distribution 

Asymmetric Cryptography
Two different asymmetric keys that are mathematically related
One public and one private key
Benefit: better key distribution
Weakness: slower 

This post will focus on Asymmetric systems.

Types of Asymmetric Systems

  

RSA

Public key algorithm

Developed at MIT  in 1978

Most popular asymmetric algorithm

Security comes from the difficulty of factoring large numbers into their original prime numbers

Often used for key exchange

Uses one way function

 “RSA is one of the first practical public-key cryptosystems and is widely used for secure data transmission. In such a cryptosystem, the encryption key is public and differs from the decryption key which is kept secret. In RSA, this asymmetry is based on the practical difficulty of factoring the product of two large prime numbers, the factoring problem.” 

One way function (Important Concept)

One way function- a mathematical function that is easier to compute in one direction than in the opposite direction (Broken glass) Trapdoor (How to put the glass back together) 

Elliptic Curve Cryptosystems 

Provides much of the same functionality as RSA: digital signatures, secure key distribution and encryption but is much more efficient Uses points on elliptic curve for values in the algorithm

"Elliptic curve cryptography (ECC) is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. ECC requires smaller keys compared to non-ECC cryptography (based on plain Galois fields) to provide equivalent security"

If you want to dig into the details of ECC check out this blog, which gives a very detailed primer on ECC,

http://andrea.corbellini.name/2015/05/17/elliptic-curve-cryptography-a-gentle-introduction/

Hashing 

One way hash- a function that takes a variable length message and produces a fixed value to ensure it was not altered 

"A hash function is any function that can be used to map data of arbitrary size to data of fixed size. The values returned by a hash function are called hash values, hash codes, digests, or simply hashes."

Hashing Algorithms 

MD2 

MD4 

MD5

SHA

HAVAL 

TIGER 

Tip: Hash functions are really important when dealing with digital forensics.They are used to ensure evidence was not tampered with or altered.

Important Crypto Terms To Know

Digital signature- ensuring the authenticity and integrity of a message through the use of hashing algorithms and asymmetric algorithms. The message digest is encrypted with the senders private key

Public key infrastructure (PKI)-  is a set of hardware, software, people, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates.

Certificate- is an electronic document that uses a digital signature to bind a public key with an identity 

Certification authority (CA)- is an entity that issues digital certificates

These topics can get quite complex and this post is really only covering the fundamentals. If you have questions let me know, if you want more cryptology posts on certain topics let me know that too....I am considering doing a post specifically on cryptology used in cryptocurrency if people want that, let me know in the comments.

I am also hoping to have a new "Tales From The Crypto" out pretty soon, so stay tuned!

Sources

https://en.wikipedia.org/wiki/Hash_function

https://en.wikipedia.org/wiki/RSA_(cryptosystem)

https://en.wikipedia.org/wiki/Elliptic_curve_cryptography

http://andrea.corbellini.name/2015/05/17/elliptic-curve-cryptography-a-gentle-introduction/

 https://www.youtube.com/channel/UCItMD0Mfb7kb4IiIhbg3fKQ

Thank you for reading Cryptology Series Part 6:Types of asymmetric Systems

If you had any trouble with terminology or the concepts involved check out the other parts of my series

Cryptology Series Part 1: Getting the Basics

Cryptology Series Part 2: History of Cryptography

Cryptology Series Part 3: Strength Of Cryptosystems 

Cryptology Series Part 4: Methods of Encryption

Cryptology Series Part 5: Types of Symmetric Systems

Part 7 of my Cryptology Series will focus on Key Management

 

Follow my blog @digicrypt if you are interested in cryptocurrency, cryptology or blockchain.

DASH: XgQ9NBonMoCPKhF37agY4W8zk7gwQFnwGV

Ether: XE04RO3I0QA5UKB31OZK4O3CK3TOT03R4TM