### Saturday, July 30, 2005

## Interesting text on public key private key security

I found this some where around the net:

Very nice explanation!

Prime factorization happens to be the foundation for secure data communications. It’s relatively easy to multiply two prime numbers together (7,817 and 7,333, for example), but no one has found an easy way to do the calculation in reverse — that is, figure out which two prime numbers can be multiplied together to equal 57,322,061.

This is what makes public-key cryptography possible. Other people can send you messages that are coded using the product of two primes, but that secret message can be deciphered only by someone who knows the two prime factors.

Your computer automatically handles all this coding and decoding in a secure electronic transaction. That’s what protects your credit card information from electronic eavesdroppers when you buy something over the Internet. But suppose the eavesdroppers had quantum computers: With all that computing power, they could figure out the prime factors of even incredibly large numbers — and crack the code.

Thus, the development of quantum computers would require a complete change in the methods used to protect information transmitted over the Internet and other “secure” communications links.

Very nice explanation!

Prime factorization happens to be the foundation for secure data communications. It’s relatively easy to multiply two prime numbers together (7,817 and 7,333, for example), but no one has found an easy way to do the calculation in reverse — that is, figure out which two prime numbers can be multiplied together to equal 57,322,061.

This is what makes public-key cryptography possible. Other people can send you messages that are coded using the product of two primes, but that secret message can be deciphered only by someone who knows the two prime factors.

Your computer automatically handles all this coding and decoding in a secure electronic transaction. That’s what protects your credit card information from electronic eavesdroppers when you buy something over the Internet. But suppose the eavesdroppers had quantum computers: With all that computing power, they could figure out the prime factors of even incredibly large numbers — and crack the code.

Thus, the development of quantum computers would require a complete change in the methods used to protect information transmitted over the Internet and other “secure” communications links.