-: Replay attacks.
A replay attack is a network-based attack
where valid data transmissions are fraudulently
or maliciously re-broadcast, repeated, or delayed.
This works a lot like a session hijack
but it's a little bit different.
With a session hijack,
the attacker is trying to modify the information
being sent and received at real time,
but with a replay attack,
we're simply trying to intercept it,
analyze it, and decide whether or not to let it
be passed on later again.
Now, for example, if I were able to capture
the session that occurs when you went in
to log into your bank with your username and password,
I could then replay that session
to the bank later on in an attempt to log in as you.
That's the idea of a replay attack.
Now, to combat a replay attack,
you should ensure that websites and devices
are using session tokens to uniquely identify
when an authentication session is occurring.
Also, if you use multi-factor authentication,
this can help prevent the ability of a log on session
to be replayed because it doesn't have that token
that has that random data that's changed every 30
to 60 seconds if you're using something
like a one-time use password
as part of your multi-factor authentication.
One place where replay attacks have been used
quite successfully, though,
is in the world of wireless authentication.
By capturing a device's handshake onto the wireless network,
you can replay it later
to gain access to that network yourself
as if you were them.
This is extremely common in the older protocols,
especially the wired equivalent privacy or WEP
when using a wireless network.
So, you should be using the latest protocols
like WPA2 to help prevent and minimize your risk.