[1] M. Krzywinski, “Port knocking from the inside
out,” Communication, 2005.
[2] R. deGraaf, J. Aycock, and M. J. Jacobson,
“Improved Port Knocking with Strong Authentication,”
21st Annu. Comput. Secur. Appl. Conf., no.
Acsac, pp. 451–462, 2005.
[3] T. Popeea, V. Olteanu, L. Gheorghe, and R. Rughinis,
“Extension of a port knocking client-server
architecture with NTP synchronization,” in
Roedunet International Conference (RoEduNet),
2011 10th, pp. 1–5, 2011.
[4] H. Al-Bahadili and A. H. Hadi, “Network Security
Using Hybrid Port Knocking,” IJCSNS, vol. 10,
no. 8, pp. 8, 2010.
[5] V. Srivastava, A. K. Keshri, A. D. Roy, V. K.
Chaurasiya, and R. Gupta, “Advanced port knocking
authentication scheme with QRC using AES,”
in Emerging Trends in Networks and Computer
Communications (ETNCC), 2011 International
Conference on, pp. 159–163, 2011.
[6] B. Maddock, “Port Knocking: An Overview of
Concepts, Issues and Implementations,” SANS
GIAC GSEC Pract. 23rd, 2004.
[7] M. Krzywinski, “Port Knocking,” A System for
Stealthy Authentication Across Closed Ports,
Available: http://www.portknocking.org/view/
about/summary, 10-Dec-2012.
[8] M. Krzywinski, “Port Knocking - Network Authentication
Across Closed Ports,” SysAdmin, vol.
12, no. 6, pp. 12–17, 2003.
[9] S. Jeanquier, “An Analysis of Port Knocking and
Single Packet Authorization MSc Thesis,” 2006.
[10] D. Worth, “COK: Cryptographic one-time knocking,”
Talk slides, Black Hat USA, 2004.
[11] OSI Reference Model, [Online]. Available: http://
standards.iso.org/ittf/Publicly Available Standards/
index.html, 24-Nov-2012.
[12] A. I. Manzanares, J. T. Marquez, J. M. Estevez-
Tapiador, and J. C. H. Castro, “Attacks on port
knocking authentication mechanism,” Comput.
Sci. Its Appl. 2005, pp. 1292–1300, 2005.
[13] M. Krzywinski, “Port Knocking,” [Online]. Available:
http://www.portknocking.org/, 12-Dec-2012.
[14] C. Hammond, “I Invented Port Knocking,” 2011.
[Online]. Available: http://blog . Chipx86 .com/
2011/02/10/i-invented-port-knocking/, 24-Dec-
2012.
[15] C. Hammond, “Knock Knock,” [Online]. Available:
http://www.advogato.org/person/chipx86/
diary/134.html, 24-Dec-2012.
[16] P. Barham, S. Hand, and R. Isaacs, “Techniques
for lightweight concealment and authentication in
IP networks,” Intel Res. Berkeley, 2002.
[17] F. of Phenoelit, “cd00r.c,” 2000. [Online]. Available:
http://www.phenoelit.org/stuff/d00rdescr.html,
22-Dec-2012.
[18] G. Hartrell, “Get ahandle oncd00r: The invisible
backdoor,” SANS Inst., no. Security 504, 2002.
[19] C. M. Nyberg, “SAdoor,” 2001. [Online]. Available:
http://cmn.listprojects.darklab.org/. 10-Jan-
2013.
[20] Creining, “Undetectable backdoor SAdoor,” 2003.
[Online]. Available: http://packetfu.org/2003/04/
undetectable-backdoor-sadoor.html, 10-Jan-2013.
[21] J.B.Ward, “The Doorman or Silent Running,”
2004 [Online], Available: http://doorman. sourceforge.
net/.
[22] C. K. T. Cappella, “Remote Server Management
Using Dynamic Port Knocking and Forwarding,”
Security, 2004.
[23] P. Iyappan, K. S. Arvind, N. Geetha, and S. Vanitha,
“Pluggable Encryption Algorithm In Secure
Shell(SSH) Protocol,” 2009 Second Int. Conf.
Emerg. Trends Eng. Technol., pp. 808–813, 2009.
[24] E. Y. Vasserman, N. Hopper, and J. Tyra,
“SilentKnock: practical, provably undetectable
authentication,” Int. J. Inf. Secur., vol. 8, no. 2, pp.
121–135, Nov. 2009.
[25] M. Rash, “Advances In Single Packet Authorization,”
ShmooCon, no. 2, 2006.
[26] J. H. Liew, S. Lee, I. Ong, H. J. Lee, and H. Lim,
“One-Time Knocking framework using SPA and
IPsec,” in Education Technology and Computer
(ICETC), 2010 2nd International Conference on,
vol. 5, pp. 205–209, 2010.
[27] F. Ali, R. Yunos, and M. Alias, “Simple port
knocking method: Against TCP replay attack and
port scanning,” Cyber Secur. Cyber Warf., pp. 247
–252, Jun. 2012.
[28] P. Mehran, E. A. Reza, and B. Laleh, “SPKT: Secure
Port Knock-Tunneling, an enhanced port security
authentication mechanism,” 2012 IEEE
Symp. Comput. Informatics, pp. 145–149, Mar.
2012.
[29] M. Pourvahab, R. E. Atani, and M. Shavanddasht,
“Port-Knocking with the usage of Web, Internet
control message protocol and Tunneling (PWIT),”
in 6th National Conference Iran"s Scientific Society
on Command, Control, Communications, Computer
and Inteligence (C4I), 2012.
[30] M. Baxter, “TCP/IP Reference,” [Online] Available:
http://nmap.org/book/tcpip-ref.html, Accessed:
10-Apr-2013.
