Man-in-the-middle attack

In cryptography and computer security, a man-in-the-middle attack (often abbreviated to MITM, MitM, MIM, MiM or MITMA) is an attack where the attacker secretly relays and possibly alters the communication between two parties who believe they are directly communicating with each other. One example is active eavesdropping, in which the attacker makes independent connections with the victims and relays messages between them to make them believe they are talking directly to each other over a private connection, when in fact the entire conversation is controlled by the attacker. The attacker must be able to intercept all relevant messages passing between the two victims and inject new ones. This is straightforward in many circumstances; for example, an attacker within reception range of an unencrypted Wi-Fi wireless access point, can insert himself as a man-in-the-middle.[1] Example of an attack[edit] Illustration of man-in-the-middle attack. Suppose Alice wishes to communicate with Bob. 1.

How Safe is SSL from MITM (Man In The Middle) Attacks? Website Technology Issues forum at WebmasterWorld The topic of SSL security on an unsecured wifi connection was brought up on on the thread about How to Secure Wordpress Sites [webmasterworld.com] and it seemed there was enough FUD swirling around this topic to start a new thread. This is intended to be educational for those that think SSL-MITM isn't possible so don't shoot the messenger as this is an educational and informative post. I'm not trying to show anyone how to launch a MITM attack, or give away all the steps required to sniff SSL. Besides, there's no need to do this because all of this information is freely available all over the internet with a simple query. From the WordPress thread mentioned above: If you can establish yourself as the MITM (Man in the Middle) you only need to dnsspoof the destination and issue a fake SSL cert as a response to the victim and then you can use SSLDUMP to decrypt the SSL stream. Wow, that was hard wasn't it? Let's do a simple diagram of how that works: The big challenge is getting in the middle.

Public key infrastructure Diagram of a public key infrastructure A public key infrastructure (PKI) is a set of hardware, software, people, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates.[1] In cryptography, a PKI is an arrangement that binds public keys with respective user identities by means of a certificate authority (CA). The user identity must be unique within each CA domain. The third-party validation authority (VA) can provide this information on behalf of CA. The binding is established through the registration and issuance process, which, depending on the assurance level of the binding, may be carried out by software at a CA or under human supervision. Design[edit] Public key cryptography is a cryptographic technique that enables users to securely communicate on an insecure public network, and reliably verify the identity of a user via digital signatures.[2] A PKI consists of:[4][6][7] Methods of certification[edit] Certificate authorities[edit]

Network packet Formatted unit of data carried by a packet-switched network Terminology[edit] Architecture[edit] The basis of the packet concept is the postal letter: the header is like the envelope, the payload is the entire content inside the envelope, and the footer would be your signature at the bottom.[3] Network design can achieve two major results by using packets: error detection and multiple host addressing.[4] Framing[edit] Communications protocols use various conventions for distinguishing the elements of a packet and for formatting the user data. Contents[edit] A packet may contain any of the following components: Addresses The routing of network packets requires two network addresses, the source address of the sending host, and the destination address of the receiving host. Error detection and correction Error detection and correction is performed at various layers in the protocol stack. At the transmitter, the calculation is performed before the packet is sent. Hop limit Length Protocol identifier

How to Create Totally Secure Cookies Securing cookies and sessions is vital to keeping an application secure. Many tutorials have been written on the subject, but as the internet (and browsers loading it) evolve so do the methods you can use to keep your application secure. In this article we’re going to break down the various components of a cookie and what they mean for security. This will include limiting the cookie to certain domains and paths on those domains, choosing what information to store, and protecting the cookie from cross site scripting exploits. In a second article we will go into more depth in how to protect everyone’s favorite cookie, the session ID. How Cookies Work Cookies are simply key/value pairs that let us get around HTTP being a stateless protocol. When the server wants to set a cookie it passes back a header named “Set-Cookie” with the key-value pair and some options. On subsequent requests the client will send along its own header to let the server know the name and value of its stored cookies.

Chapter 14 - Encrypting network traffic (Virtual Private Networks) with IPSec By Kurt Seifried, kurt@seifried.org, Copyright Kurt Seifried With sensitive data moving across public networks some form of encryption is needed to protect the data, provide authentication, and prevent spoofing/etc. The emerging standard for this problem is IPSec (IP Security), which has broad industry support and a recognized set of RFC's laying down the rules. Unfortunately one of the major areas of IPSec is key management, and this is one area where many vendors have trouble interoperating, so if you are considering a hetrogenous network do plenty of testing beforehand. The good news is most vendors support IPSec, many "out of the box", and there are numerous free to cheap clients for Windows 95/98/NT (2000 has built in support). The first decision needed when implementing IPSec is to decide what traffic you want to encrypt. [ Back | TOC | Forwards]

Internet Protocol Communication protocol that allows connections between networks The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. The first major version of IP, Internet Protocol version 4 (IPv4), is the dominant protocol of the Internet. Its successor is Internet Protocol version 6 (IPv6), which has been in increasing deployment on the public Internet since around 2006.[1] The Internet Protocol is responsible for addressing host interfaces, encapsulating data into datagrams (including fragmentation and reassembly) and routing datagrams from a source host interface to a destination host interface across one or more IP networks.[2] For these purposes, the Internet Protocol defines the format of packets and provides an addressing system. There are four principal addressing methods in the Internet Protocol:

Session management Temporary context for interactive information interchange In computer science and networking in particular, a session is a time-delimited two-way link, a practical (relatively high) layer in the TCP/IP protocol enabling interactive expression and information exchange between two or more communication devices or ends – be they computers, automated systems, or live active users (see login session). A session is established at a certain point in time, and then ‘torn down’ - brought to an end - at some later point. An established communication session may involve more than one message in each direction. A session is typically stateful, meaning that at least one of the communicating parties needs to hold current state information and save information about the session history to be able to communicate, as opposed to stateless communication, where the communication consists of independent requests with responses. Software implementation [edit] Server-side web sessions Client-side web sessions

SSH File Transfer Protocol In computing, the SSH File Transfer Protocol (also Secure File Transfer Protocol, or SFTP) is a network protocol that provides file access, file transfer, and file management functionalities over any reliable data stream. It was designed by the Internet Engineering Task Force (IETF) as an extension of the Secure Shell protocol (SSH) version 2.0 to provide secure file transfer capability, but is also intended to be usable with other protocols. The IETF Internet Draft states that even though this protocol is described in the context of the SSH-2 protocol, it could be used in a number of different applications, such as secure file transfer over Transport Layer Security (TLS) and transfer of management information in VPN applications. This protocol assumes that it is run over a secure channel, such as SSH, that the server has already authenticated the client, and that the identity of the client user is available to the protocol. Capabilities[edit] History and development[edit] Version 3[edit]