What is the role of cryptography in ecommerce?

Encryption is a generic term that

refers to the act of encoding data, in

this context so that those data can be

securely transmitted via the internet.

As Professor Lawrence Lessig of

Stanford Law School put it, "Here is

something that will sound very

extreme but is at most, I think, a slight

exaggeration: encryption technologies

are the most important technological

breakthrough in the last one

thousand years." Encryption can

protect the data at the simplest level

by preventing other people from

reading the data. In the event that

someone intercepts a data

transmission and manages to deceive

any user identification scheme, the

data that they see appears to be

gibberish without a way to decode it.

Encryption technologies can help in

other ways as well, by establishing the

identity of users (or abusers); control

the unauthorized transmission or

forwarding of data; verify the integrity

of the data (i.e., that it has not been

altered in any way); and ensure that

users take responsibility for data that

they have transmitted. Encryption can

therefore be used either to keep

communications secret (defensively)

or to identify people involved in

communications (offensively).