I)ruid [CAU] - Steganography Primer

Examples of Usable Header Fields

Using the IP header’s packet ID field within a single session

Using TCP SYN packet’s initial sequence number (ISN) across multiple sessions

Various types of ICMP have undefined header space between fields


		•Some examples of usable network header fields include:
			•The IPID field in the IP header (RFC 791)
			•TCP SYN packet’s initial sequence number (ISN) (RFC 793). Nomad’s Ncovert tool’s method simulates a SYN scan and uses this field.
			•Various ICMP types have different amounts of unused space in their headers (RFC 792)
			•Routing control messages have various fields that can be used.