what's Encryption ? | BHS

Encryption is the process of disguising information to
make it unreadable by those who lack the tools to
decipher it. This process has been used for centuries
to send secret messages. It has been traced back to
the Romans and has been actively used by the
military ever since. Encryption has become increasingly important as a way to keep information
sent over the Internet private.

One common encryption system substitutes numbers
for letters. This substitution procedure is called a key.
Normally, the sender and the receiver agree on a key,
and this key remains secret. Only those who know the
key can encode and decode messages. This is called
symmetric encryption, since messages use a single key for both encryption and decryption.

Another encryption method, called asymmetric
encryption, has become popular for online
transactions - you use it every time you check your
bank account online or do online shopping.
Asymmetric encryption uses a separate pair of keys
for each user: a private key known only to the receiver and a public key known by everybody. A
sender encrypts messages using the receiver's public
key, but only the receiver can decipher it with her
private key. Although it sounds more complicated, the
principle is the same: a secret key is required to be
able to understand the message.