**Primecoin is going for a whole new approach**: ‘*A new type of proof-of-work based on searching for prime numbers is introduced in peer-to-peer cryptocurrency designs. Three types of prime chains known as Cunningham chain of first kind, Cunningham chain of second kind and bi-twin chain are qualified as proof-of-work. Prime chain is linked to block hash to preserve the security property of Nakamoto’s Bitcoin, while a continuous difficulty evaluation scheme is designed to allow prime chain to act as adjustable-difficulty proof-of-work in a Bitcoin like cryptocurrency’*, says Sunny King in the introduction paper of the new digital currency. Primecoin is on the search for the unthinkable, long chains of prime numbers.

## Scientific value

Primecoin is the first cryptocurrency on the market with non-hashcash proof-of-work, generating additional potential scientific value from the mining work. This research is meant to pave the way for other proof-of-work types with diverse scientific computing values to emerge. Mining Bitcoin, Litecoin or other Cryptocurrencies is king of meaningless, but mining Primecoin is not only a way to find blocks, but also interesting for many other purposus, actually Primecoin is already breaking new world records. Read more about Primecoin @ PPcoin.org/primecoin.

## About prime numbers

Let’s have look at the prime numbers where it is all about. A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example, 5 is prime because only 1 and 5 evenly divide it, whereas 6 is composite because it has the divisors 2 and 3 in addition to 1 and 6. The fundamental theorem of arithmetic establishes the central role of primes in number theory: any integer greater than 1 can be expressed as a product of primes that is unique up to ordering. The uniqueness in this theorem requires excluding 1 as a prime because one can include arbitrarily many copies of 1 in any factorization, e.g., 3, 1 × 3, 1 × 1 × 3, etc. are all valid factorizations of 3. More @ Wikipedia.

## A great beginning

Sunny King, also founder of PPcoin, did a great job with Primecoin. Since it started, in the beginning of July 2013, the price of Primecoin has risen significantly. If you want to trade Primecoin (also known as XMP) you can do so here. 1 Primecoin (XMP) is almost worth 0.01 Bitcoin (BTC). Or about $0,85. At Vircurex you can trade the following currency pairs:

- XPM/EUR
- XPM/USD
- BTC/XPM
- DGC/XPM
- DVC/XPM
- FRC/XPM
- FTC/XPM
- IXC/XPM
- LTC/XPM
- NMC/XPM
- NVC/XPM
- PPC/XPM
- TRC/XPM