Problem
The very first step in the SHA1 algorithm is to pad the message so that it is a multiple of 512 bits. This padding occurs as follows (from NIST FPS 180-2): Suppose the length of the message M is L bits. Append bit 1 to the end of the message, followed by K zero bits where K is the smallest non-negative solution to
L + 1 + K ≡ 448 (mod 512)
Next append a 64-bit block that is a binary representation of the length integer L. For example,
Message = "abc"
length L = 24 bits
01100001 01100010 01100011 1 00......000 00...011000
a b c <---423---> <---64---->
<------------------- 512 ------------------------------>
Now here is the question:
1) Why do we include the length of the message in the calculation of the hash code?
2) Why is TLS/SSL tunneling for VPN becoming more popular over IPSEC tunning?
3) Assuming you wanted to capture and analyze network traffic at your company but the VLAN is spread over 3 switches. What are some ways you could get around this?
4) In a Shrew DoS attack, the attacker only floods the target with connection request for a very short period of time (the RTT time) every so often (RTO time). Why not just send a flood of connections until the server breaks?
5) Describe how an attacker can use IP Spoofing and TCP Syn attack together to compromise two servers at once.