what is meant by challenge response?

Answer 1

In the military a 'Challenge -Response' is a password to identify friend or foe.
" Typically the challenge "Who goes there?", the response " Sergeant Jones E company."

It could be, the challenge "Tiger" the response " Claw"

Yours: Grumpy

Answer 2

A challenge is called out by a sentry, "Halt, who goes there" The response is either predetermined such as a code word or phrase or the approaching party will identify regiment and battalion with number in the party, "3rd Batt.,PPCLI Five returning from leave. In the field or while under alert a challenge and the proper countersign will be issued by command. The challenge maybe Currie and the countersign Vimy. If the proper countersign is not given to the challenge the approaching party must be considered hostile.

Answer 3

The most common way of doing a challenge response in IT is for passwords. The idea is that someone eavesdropping on the connection won't be able to replay your password.

Suppose my password was the word 'password'.
A challenge-response system won't ask me for my whole password, it will instead ask for part of my password eg
Send digits 1, 3, and 5 and my system should respond with 'psw'.
The second time it might ask send digits 3,6,7 and my system should reply 'sor'. So if you're listening on my connection trying to get my password you're going to be there a while which gives me a better chance of detecting it or changing my password before you get it all.

Answer 4

it's what goes on at the begininning of a network communication: each host wants to maker sure he is talking to the correct person.
It's also used in some credit cards: the reader authenticate the card by asking a question that only the card should be able to answer, then the card asks a question to the reader. after that they trust each other and can exchange data freely.

Answer 5

Thats essentially what a challange response in IT security is as well, essentially once a session is created between two users, some protocols include a challange/response method to ensure your talking to who you think your talking to and not a hacker.

Answer 6

Looks like someone used shorthand to say someone did "whatever" in response to a challenge.

He called the "whatever" a challenge-response.