Description:
GC&CS Sixta History. An account of the work of the Traffic Analysis Party at Bletchley Park. This was named SIXTA (Hut 6 Traffic Analysis) in November 1943 for its analysis role in supporting Hut 6 (Army and Air Force)
Date: 1939 Sep 01 - 1945 Aug 30
Held by: Creating government department or its successor, not available at The National Archives
Legal status: Public Record(s)
Closure status: Closed Or Retained Document, Open Description
Access conditions: Retained by Department under Section 3.4
It will be understood from the nature of the Enigma machine that, having been given a replica Enigma by the Poles, complete with a set of rotors and their internal wiring, the task confronting Dillwyn Knox and Alan Turing, the primary British cryptanalysts, was to determine the particular settings of the Enigma machine used to encipher a particular message. Turing and Knox considered three possible methods of attack:
How to encrypt/decrypt with Enigma
We'll start with a step-by-step guide to decrypting a known message. You can see the result of these steps in CyberChef here. Let's say that our message is as follows:
XTSYN WAEUG EZALY NRQIM AMLZX MFUOD AWXLY LZCUZ QOQBQ JLCPK NDDRW F
And that we've been told that a German service Enigma is in use with the following settings:
Rotors III, II, and IV, reflector B, ring settings (Ringstellung in German) KNG, plugboard (Steckerbrett)AH CO DE GZ IJ KM LQ NY PS TW, and finally the rotors are set to OPM.
Enigma settings are generally given left-to-right. Therefore, you should ensure the 3-rotor Enigma is selected in the first dropdown menu, and then use the dropdown menus to put rotor III in the 1st rotor slot, II in the 2nd, and IV in the 3rd, and pick B in the reflector slot. In the ring setting and initial value boxes for the 1st rotor, put K and O respectively, N and P in the 2nd, and G and M in the 3rd. Copy the plugboard settings AH CO DE GZ IJ KM LQ NY PS TW into the plugboard box. Finally, paste the message into the input window.
All passwords are first hashed before being stored. A hash is a one way mathematical function that transforms an input into an output. It has the property that the same input will always result in the same output. Modern hashing algorithms are very difficult to break, so one feasible way to discover a password is to perform a brute force attack on the hash.
There are a few factors used to compute how long a given password will take to brute force. To compute the time it will take, you must know the length of the password, the character set used, and how many hashes can be checked every second.
On a modern computer (8 core, 2.8 GHz) using the SHA512 hashing algorithm, it takes about 0.0017 milliseconds to compute a hash. This translates to about 1.7*10^-6 seconds per password, or 588235 passwords per second. Although we will not use the metric in this article, it is important to note that a GPU, or 3D card, can calculate hashes at a speed 50-100 times greater than a computer. For the purposes of this KB article, we will calculate how long given passwords can be cracked using a single modern computer. We also calculate how long they can be cracked using a supercomputer, which is approximately equivalent to a botnet with 100000 computers. Modern supercomputers can be up to 150000 faster than their desktop counterparts and a 100000 computer botnet is feasible; the largest botnet to date is estimated to have 12 million computers. We also assume that on average, the password will be cracked when half of the possible passwords are checked.
To demonstrate the importance of password complexity, let's start with a pincode password such as "123456789". In this case, the character set (0123456789) consists of 10 characters. For a 9 digit password using this character set, there are 10^9 possible password combinations. Therefore, it will take (1.710^-6 10^9) seconds / 2, or 14.17 minutes, to break this password on average. On a supercomputer or botnet, we divide this by 100000, so it would take 0.0085 seconds to break a password. //
o, even if you use a very secure set of characters, your password should be at least 10 characters long. To break a 10 character password that uses letters, numbers, and symbols, such as "%ZBGbv]8g?", it would take (1.710^-6 80^10) seconds / 2 or 289217 years. This would take about 3 years on a supercomputer or botnet.
PrivateBin is a minimalist, open source online pastebin where the server has zero knowledge of pasted data.
Data is encrypted and decrypted in the browser using 256bit AES in Galois Counter mode.
This is a fork of ZeroBin, originally developed by Sébastien Sauvage. ZeroBin was refactored to allow easier and cleaner extensions. PrivateBin has many more features than the original ZeroBin. It is, however, still fully compatible to the original ZeroBin 0.19 data storage scheme.
What PrivateBin provides
As a server administrator you don't have to worry if your users post content that is considered illegal in your country. You have no knowledge of any of the pastes content. If requested or enforced, you can delete any paste from your system.
Pastebin-like system to store text documents, code samples, etc.
Encryption of data sent to server.
Possibility to set a password which is required to read the paste. It further protects a paste and prevents people stumbling upon your paste's link from being able to read it without the password