Cryptography is the art and science of keeping information secret. It involves
writing or solving ciphers. A cipher is a disguised way of communicating.
Cryptography refers to mathematically based encryption methods that keep
data away from the prying eyes of criminals or enemy governments.
"Modern society could not operate without information security," says cryptographer
Arthur Low.
Today's businesses and governments use what is called "strong" encryption.
This type of encryption is created using applied mathematics. Strong encryption
was once used solely for military purposes. But in today's wired world, encryption
is needed for all kinds of uses.
"There's lots of reasons why we need privacy, not just because we want
to make money or because we want to conduct negotiations in secret -- just
because that's the way society really works," says Low. "It doesn't work very
well if everything is out in the open."
Every time you shop online, you're using encryption technology. Online
storefronts, such as iTunes, are set up to secure sessions automatically.
That protects people's credit card information.
Cryptography provides privacy for people and corporations. It encourages
trust between businesses. It keeps hackers out of important data systems.
Most cryptography is done by computer software and specialized hardware
devices. It's not the cryptographer who sits there figuring out a cipher one
word at a time.
"I think a person who would be really good in the field of cryptography,
[doing] coding and what's called cryptanalysis, would be mathematically gifted
and would also be very interested in patterns and problem solving," says Low.
"The ability to concentrate on problems for a long time" is important,
says cryptographer Greg Rose. "These days you need some kind of programming
skills as well."
Encoding a message so that its contents are hidden from outsiders is called
encryption. Once the message is encrypted, it is called ciphertext. Turning
a message from ciphertext back into plaintext is called decryption. Governing
both processes is something called a key -- and that key is based on mathematical
algorithms.
Cryptographers figure out different ways to encrypt information. Those
who decipher information from encrypted messages without knowing the original
key are called cryptanalysts.
The most important requirements for cryptographers are a mind for math
and the ability to focus on complex problems for extended periods.
Cryptography is a rapidly changing field. The need to safeguard the online
world is only going to become more important over time.
"The kinds of things modern cryptography can do -- secure multi-party computation,
fully homomorphic encryption, anonymous credentials, electronic cash -- will
blow you away," says cryptography professor Anna Lysyanskaya.
"But a lot of it isn't being used in practice simply because people don't
know it's possible," she says. "So tell everyone you know about it, and you
will help bring about a cryptographic revolution!"