Category: Cyber security

Cyber Security at the movies: Catwoman

SPOILER ALERT

A cat sat on a branch silhouetted by an orange moon
Image by bess.hamiti@gmail.com from Pixabay

The 2004 film Catwoman, starring Halle Berry as Patience Phillips (and Catwoman), has been voted as one of the worst films of all time, and has won multiple Razzies (Golden Raspberry Awards) – Halle Berry accepted hers while holding her Best Actress Academy Award. Now, however, it has a bit of a cult following. It did at least feature an African American woman as the lead, in a superhero film, possibly for the first time, and came long before Black Panther. Whether it deserves either accolades or condemnation, it certainly features some of the worst cyber-physical security seen in a film by a corporate giant. So what can we learn about cyber-physical security from the film?

The weakest link

The plot is based around the cosmetics firm Hedare Beauty and its development and product launch of a new face cream that reverses the affects of aging. Clearly, a big corporate player, the firm has a massive team at their headquarters that includes artist Patience working on PR, but also a massive research and industrial complex, developing testing and manufacturing its products. Now, cyber-criminals do not just include hackers out to cause anarchy or extort money from people, they also include people working for companies, sometimes supported by their countries, doing industrial espionage: trying to steal research and development secrets. By stealing the designs or product formulae of their competitors, such companies aim to save the massive time and development costs of doing it themselves. They then quickly produce rip-off products to steal the market. Gaining secrets can also gain criminals advantage through insider trading, buying and selling shares, so making money on the back of secret information about what is about to happen. Companies, therefore, have to take industrial espionage seriously, and that means taking cyber-security seriously too.

In Catwoman, the company, Hedare Beauty, have the normal kinds of industrial secret but also a big nasty one too, so their bosses have even more reason to put a lot of effort into security. They certainly have lots of heavies with guns looking to shoot people. However, their physical security is actually totally lax.

This is first seen when Patience’s love interest, Detective Tom Lone, merrily walks into the corporate headquarters and up to her open plan desk where she is working on the product launch to ask her for a date. How did he get in? Why isn’t anyone accompanying him in such a sensitive area especially days before a crucial launch? Where is his visitor’s pass and why isn’t he being challenged. Perhaps this can be put down to being a cop (perhaps he waived his badge about) but still someone senior should have accompanied him surely (and is returning Patience’s purse (his excuse) really a good enough reason to bypass security whoever you are?)

However, even if we let that go, later Patience has to deliver some artwork by midnight to the boss out at the industrial complex. That is where the real secrets, good and bad, are. When she gets there the foyer is locked and dark with no one on duty. In many thrillers, the heroes have to use sophisticated gadgets, amazing technical or physical skill, or subterfuge to overcome the massively sophisticated hi-tech security. Patience, by contrast, just wanders round the back looking for another way in and finds a fire door ajar. This allows her to both enter and ultimately make it to the heart of the building where secrets are being discussed. As a result she overhears (if accidentally) something she should not hear…

Perhaps the most important principle of cyber-security is that it is as weak as its weakest link. You can have all the high tech multi-factor biometric authentication systems, impossible to crack encryption, experienced and well-trained former SAS guards patrolling the foyer, and so on, but if you leave a back door open then the criminals will just ignore all your high tech security and walk in through that one back door. That is exactly what Patience does. There is no point as, for example, I have seen in real life, checking everyones access cards on a main gate, when there is an un-manned side gate. The criminals aren’t going to even try to enter through the front gate. Likewise, if you have a weak point in your cyber-security system, it does not matter how massively strong the rest is.

It is also better to think not of just cyber-security, anyway, but of cyber-physical security. The weakest links can just as easily be to do with physical security as with the computerised part – like the open door Patience found, or letting someone claiming to be a Detective to walk around anywhere in the building. Once the “Detective” is in, they can gather information to launch other attacks from other weak points they now have access to (like passwords written on post-it notes, an access card left on someone’s desk, or computers left unlocked, for example). So poor physical security can be the weak link allowing a backdoor into the computer system.

Another point from the film is that, whether cyber security or physical security, just being “inside” (a computer or a building) should not give access to everything. As you move through a building or through a computer system, there should be more locks to get through, more authentication tests to pass, with different levels of access for different people

Patience should never have got into the building, but even if she had, she shouldn’t have got further than the corridor. Luckily (!) for her, she did with the ultimate result that she gained superhuman powers and became Catwoman, so perhaps sometimes bad security is not all bad (if only in a world where people can gain superpowers from cats).

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The Knights Templar Cipher

The Knights Templar flag. A red cross on a black (above) and white (below (background)
The flag of the Knight’s Templar. Image by CS4FN

The Knights Templar were a 12th century order of catholic warrior monks, more accurately if convolutedly called “The Poor Fellow-Soldiers of Christ and of the Temple of Solomon” though they weren’t exactly poor. In addition to their original role of protecting catholic pilgrims heading to Jerusalem from robbery and murder, they also acted as a kind of international banker to support their main role. They laid some important foundations of modern international banking in the process. In particular, they invented a way to move money (or gold) around safely, without ever actually moving it anywhere. That sounds like a magic trick! Did they use some supposed mystical magic powers to do this? No, they kept the actual money given to them in the nearest of their large network of 1000 or so headquarters and forts around the continent. The money didn’t have to move anywhere. They then gave the person a note to hand in at their headquarters in another country. It promised that the Knights there would give them the equivalent amount from their money store when asked and given the note. The Knights there just swapped them the money for that note. This worked as long as they had a suitable store of money in each location, which of course would be topped up each time someone wanted to move money from that point. This is a simple version of how international banking works now. A British 20 pound note just promises to pay the bearer an equivalent amount, and without that promise (and people’s belief in it) it is just a piece of paper. It is just a similar promissory note, except people now just swap notes, treating it as money in its own right. Similarly, the banks don’t actually move any gold or other physical form of money about when you pay a shop with your debit card or banking app. They just move information equivalent to those promissory notes embodied in the transaction, around a network (though a computer one rather than a network of forts connected by roads).

There is a problem though with moving money from one person to another in this way using notes. If someone steals the note then it is potentially as valuable to them as actually stealing the chest of gold left in the original fort (just as stealing a 20 pound note is). In the Templar’s time the thief would just need to take it to a Templar headquarters and swap it for money just as the original owner would have done (a bit risky perhaps, given how fearsome the Templars were, but potentially possible!). Worse though, without a system to protect from this kind of attack, a thief could copy the note and then ask for the money repeatedly!

However, the Templars are know to have used encryption in their communications. The notes may therefore have been encrypted too and if so that would have made them useless if stolen. Banks now encrypt all those messages that move money about computer networks for the same reason. If only the Templar’s could read their notes (as only the Templar’s knew the key to their code), then only they could know it even was promising money. That doesn’t fully make it secure though, perhaps a thief could guess it was such a note, and if so what is to stop them then trying to cash it in (apart from the risk of being wrong). You would need something more. A simple possibility is the person with the note would need to know the encrypted amount that was contained somewhere within it. If they didn’t ask for the right amount then they couldn’t have handed over the money in the first place. They would reveal themselves as a thief!

Modern banks have to deal with similar problems even though modern financial transactions are all encrypted. Simple encryption alone is still not enough, protocols (special algorithms) are needed to prevent wide ranging kinds of attack being possible. Banks also need to use better ciphers than those from the Middle Ages, as today we can quickly crack ciphers as simple as the Templar Cipher. Banking is all done differently in detail today, but the ideas behind what is done and why are the same.

Can you crack the Templars’ cipher and decrypt the message below? One way might be using frequency analysis. The most common letters in English are likely (if not definitely) the most common in the message. E is most frequent in English, so which symbol might stand for E? Frequency analysis had been known for several hundred years before the Templars used ciphers (at least by the Arabs, though the Templars weren’t exactly their friends!), so it is actually possible even then that the Templars’ messages might be cracked, unknown to them. It was an Arabian scholar called Al Kindi, who actually invented frequency analysis (or at least was the earliest known person to write about it in his manuscript “On Deciphering Cryptographic Messages”.) Another way to crack the code might be to look for cribs – what words might be included in the message if it is a promissory note? Using both together may give you a good chance of decrypting the message. If you can’t crack their code (there is a big clue in this article), the key is given at the end if you scroll down. Use it to then decrypt the message.

Templar Cipher Puzzle using triangles, diamonds and other symbols.

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Scroll down for the solutions

Solutions: The Key

The Templar’s cipher uses symbols based on their flag’s triangles. To encrypt a message swap letters for symbols. (They had no J).

The cipher mapping symbols to letters§§

Can you decrypt the message given the above key? Here is an example – the message HELLO as encrypted in this cipher.

HELLO in the cipher

Scroll down further for what the message says…

Solutions: The Message

The message reads …

GIVE KING PHILIP OF FRANCE ONE HUNDRED GOLD PIECES


Hacking DNA

A jigsaw of DNA with peices missing
Image by Arek Socha from Pixabay

DNA is the molecule of life. Our DNA stores the information of how to create us. Now it can be hacked.

DNA consists of two strands coiling round each other in a double helix. It’s made of four building blocks, or ‘nucleotides’, labelled A, C, G, T. Different orders of letters gives the information of how to build each unique creature, you and me included. Sequences of DNA are analysed in labs by a machine called a gene sequencer. It works out the order of the letters and so tells us what’s in the DNA. When biologists talk of sequencing the human (or another animal or plant’s) genome they mean using a gene sequencer to work out the specific sequences in the DNA for that species. They are also used by forensic scientists to work out who might have been at the scene of a crime, and to predict whether a person has genetic disorders that might lead to disease.

DNA can be used to store information other than that of life: any information in fact. This may be the future of data storage. Computers use a code made of 0s and 1s. There is no reason why you can’t encode all the same information using A, C, G, T instead. For example, a string of 1s and 0s might be encoded by having each pair of bits represented by one of the four nucleotides: 00 = A, 01 = C, 10 = G and 11 = T. The idea has been demonstrated by Harvard scientists who stored a video clip in DNA.

It also leads to whole new cyber-security threats. A program is just data too, so can be stored in DNA sequences, for example. Researchers from the University of Washington have managed to hide a malicious program inside DNA that can attack the gene sequencer itself!

The gene sequencer not only works out the sequence of DNA symbols. As it is a computer, it converts it into a binary form that can then be processed as normal. As DNA sequences are long, the sequencer compresses them. The attack made use of a common bug found in programs that malware often uses: ‘buffer overflow’ errors. These arise when the person writing a program includes instructions to set aside a fixed amount of space to store data, but then doesn’t include code to make sure only that amount of data is stored. If more data is stored then it overflows into the memory area beyond that allocated to it. If executable code is stored there, then the effect can be to overwrite the program with new malicious instructions.

When the gene sequencer reaches that malware DNA, the converted program emerges and is converted back into 1s and 0s. If those bits are treated as instructions and executed, it launches its attack and takes control of the computer that runs the sequencer. In principle, an attack like this could be used to fake results for subsequent DNA tests, subverting court cases, disrupt hospital testing, steal sensitive genetic data, or corrupt DNA-based memory.

Fortunately, the risks of exactly this attack causing any problems in the real world are very low but the team wanted to highlight the potential for DNA based attacks, generally. They pointed out how lax the development processes and controls were for much of the software used in these labs. The bigger risk right now is probably from scientists falling for spear phishing scams (where fake emails pretending to be from someone you know take you to a malware website) or just forgetting to change the default password on the sequencer.

Paul Curzon, Queen Mary University of London

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Password strength and information entropy

Comparison of the password strength of Tr0ub4dor&3 (easy to guess, difficult to remember) and correcthorsebatterystaple (hard to guess but easy to remember if you turn it into a picture)
CREDIT: Randall Munroe, xkcd.com https://xkcd.com/936 – reprinted under a CC Attribution-NonCommercial 2.5 License

How do you decide whether a password is strong? Computer scientists have a mathematical way to do it. Based on an idea called information entropy it’s part of “Information Theory”, invented by electrical engineer Claude Shannon back in 1948. This XKCD cartoon for computer scientists uses this idea to compare two different password. Unless you understand information theory the detail is a bit mind blowing to work out what is going on though… so let’s explain the computer science!

Entropy is based on the number of guesses someone would need to make trying all the possibilities for a password one at a time – doing what computer scientists call a brute force attack. Think about a PIN on a mobile phone or cash point. Suppose it was a single digit – there would be 10 possibilities to try. If 2-digit PINS were required then there are now 100 different possibilities. With the normal 4 digits you need 10,000 (10^4 = 10x10x10x10) guesses to be sure of getting it. Different symbol sets lead to more possibilities. If you had to use lower case letters instead of digits, there are 26 possibilities for length 1 so over 450,000 (26^4 = 26x26x26x26) guesses needed for the 4 letter password. If upper case letters are possible that goes up to more than 7 million (52 letters so 52^4 = 52x52x52x52) guesses. If you know they used a word though you don’t have to try all the possibilities, just the words. There are only about 5000 of those, so far fewer guesses needed. So password strength depends on the number of symbols that could be used, but also whether the PIN or password was chosen randomly (words aren’t a random sequence of letters!)

To make everything standard, Shannon used binary to do entropy calculations so assumed a symbol set of only 0 and 1 (so all the answers become powers of 2 because he used 2 symbols). He then measured them in ‘bits’ needed to count all the guesses. Any other groups of symbols are converted to binary first. If a cashpoint only had buttons A, B, C and D for PINs, then to do the calculation you count those 4 options in binary: 00 (A), 01 (B), 10 (C), 11 (D) and see you need 2 bits to do it (2^2 = 2×2 choices). Real cashpoints have 10 digits and need just over 3 bits to represent all of a 1 digit PIN (2^3 = 2x2x2 = 8 so not enough, 2^4 = 2x2x2x2 = 16 so more than you need so the answer is more than 3 but less than 4). It’s entropy would be just over 3. To count the possibilities for a 4-digit PIN you need just over 13 bits, so that is its entropy. The lower case alphabet needs just under 6 bits to store the number of possibilities, so entropy is about 6, and so on.

So entropy is not measured directly in terms of guesses (which would be very big numbers) but instead indirectly in terms of bits. If you determine the entropy to be 28 bits (as in the cartoon), that means the number of different possibilities to guess would fit in 28 bits if each guess was given its own unique binary code. 28 bits of binary can be used to represent over 268 million different things (2^28), so that is the number of guesses actually needed. It is a lot of guesses but not so many a computer couldn’t try them all fairly quickly as the cartoon points out!

Where do those 28 bits come from? Well they assume the hacker is just trying to crack passwords that follow a common pattern people use (so are not that random). The hacker assumes the person did the following: Take a word; maybe make the first letter a capital; swap digits in place of some similar looking letters; and finally add a symbol and letter at the end. It follows the general advice for passwords, and looks random … but is it?

How do we work out the entropy of a password invented that way? First, think about the base word the password is built around. They estimate it as 16 bits for an up to 9 letter word of lower-case letters, so are assuming there are 2^16 (i.e. 65,000) possible such base words. There are about 40,000 nine letter words in English, so that’s an over estimate if you are assuming you know the length. Perhaps not if you assume things like fictional names and shorter words are possible.

As the pattern followed is that the first letter could be uppercase, that adds 1 more bit for the two guesses now needed for each word tried: check if it’s upper-case, then check if it’s lower-case. Similarly, as any letter ‘o’ might have been swapped for 0, and any ‘a’ for 4 (as people commonly do) this adds 3 more bits (assuming there are at most 3 such opportunities per word). Finally, we need 3 bits for the 9 possible digits and another 4 bits for the common punctuation characters added on the end. Another bit is added for the two possible orders of punctuation and digit. Add up all those bits and we have the 28 bits suggested in the cartoon (where bits are represented by little squares).

Now do a similar calculation for the other way of creating passwords suggested in the cartoon. If there are only about 2000 really common words a person might choose from, we need 11 bits per word. If we string 4 such words together completely at random (not following a recognisable phrase with no link between the words) we get the much larger entropy of 44 bits overall. More bits means harder to crack, so this password will be much, much harder than the first. It takes over 17 trillion guesses rather than 268 million.


The serious joke of the cartoon is that the rules we are told to follow leads to people creating passwords that are not very random at all, precisely because they have been created following rules. That means they are easy to crack (but still hard to remember). If instead you used the 4 longish and unconnected word method which doesn’t obey any of the rules we are told to follow, you actually get a password that is much easier to remember (if you turn it into a surreal picture and remember the picture), but harder to crack because it actually has more randomness in it! That is the real lesson. How ever you create a password, it has to have lots of randomness for it to be strong. Entropy gives you a way to check how well you have done.

Paul Curzon, Queen Mary University of London

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He attacked me with a dictionary!

Letters in an unreadable muddle
Image by JL G from Pixabay

You might be surprised at how many people have something short, simple (and stupid!) like ‘password’ as their password. Some people add a number to make it harder to guess (‘password1’) but unfortunately that doesn’t help. For decades the official advice has been to use a mixture of lower (abc) and upper case (ABC) characters as well as numbers (123) and special characters (such as & or ^). To meet these rules some people substitute letters for numbers (for example 0 for O or 4 for A and so on). Following these rules might lead you to create something like “P4ssW0^d1” which looks like it might be difficult to crack, but isn’t. The problem is that people tend to use the same substitutions so password-crackers can predict, and so break, them too.

Hackers know the really common passwords people use like ‘password’, ‘qwerty’ and ‘12345678’ (and more) so will just try them as a matter of course until they very quickly come across one of the many suckers who used one. Even apparently less obvious passwords can be easy to crack, though. The classic algorithm used is a ‘dictionary attack’.

The simple version of this is to run a program that just tries each word in an online dictionary one at a time as a password until it finds a word that works. It takes a program fractions of seconds to check every word like this. Using foreign words doesn’t help as hackers make dictionaries by combining those for every known language into one big universal dictionary. That might seem like a lot of words but it’s not for a computer.

You might think you can use imaginary words from fiction instead – names of characters in Lord of the Rings, perhaps, or the names of famous people. However, it is easy to compile lists of words like that too and add them to the password cracking dictionary. If it is a word somewhere on the web then it will be in a dictionary for hacking use.

Going a step further, a hacking program can take all these words and create versions with numbers added, 4 swapped for A, and so on. These new potential passwords become part of the attack dictionary too. More can be added by taking short words and combining them, including ones that appear in well known phrases like ‘starwars’ or ‘tobeornottobe’.

The list gets bigger and bigger, but computers are fast, and hackers are patient, so that’s no big deal…so make sure your password isn’t in their dictionary!

– Jo Brodie and Paul Curzon, Queen Mary University of London

from the archive

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Ninja White Hat Hacking

Female engineer working at a computer
Image by This_is_Engineering from Pixabay

Computer hackers are the bad guys, aren’t they? They cause mayhem: shutting down websites, releasing classified information, stealing credit card numbers, spreading viruses. They can cause lots of harm, even when they don’t mean to. Not all hackers are bad though. Some, called white hat hackers, are ethical hackers, paid by companies to test their security by actively trying to break in – it’s called penetration testing. It’s not just business though, it was also turned into a card game.

Perhaps the most famous white hat hacker is Kevin Mitnick. He started out as a bad guy – the most-wanted computer criminal in the US. Eventually the FBI caught him, and after spending 5-years in prison he reformed and became a white hat hacker who now runs his own computer security company. The way he hacked systems had nothing to do with computer skills and everything to do with language skills. He did what’s called social engineering. A social engineer uses their skills of persuasion to con people into telling them confidential information or maybe even actually doing things for them like downloading a program that contains spyware code. Professional white hat hackers have to have all round skills though: network, hardware or software hacking skills, not just social engineering ones. They need to understand a wide range of potential threats if they are to properly test a company’s security and help them fix all the vulnerabilities.

Breaking the law and ending up in jail, like Kevin Mitnik, isn’t a great way to learn the skills for your long-term career though. A more normal way to become an expert is to go to university and take classes. Wouldn’t playing games be a much more fun way to learn than sitting in lectures, though? That was what Tamara Denning, Tadayoshi Kohno, and Adam Shostack, computer security experts from the University of Washington, wondered. As a result, they teamed up with Steve Jackson Games and came up with a card game Control-Alt-Hack(TM) (www.controlalthack.com), sadly no longer available. It was based on the cult tabletop card game, Ninja Burger. Rather than being part of a Ninja Burger Delivery team as in that game, in Control-Alt-Hack(TM) you are an ethical white hat hacker working for an elite security company. You have to complete white hat missions using your Ninja hacking skills: from shutting down an energy company to turning a robotic vacuum cleaner into a pet. The game is lots of fun, but the idea was that by playing it you would understand a lot more of about the part that computer security plays in everyones lives and about the kinds of threats that security experts have to protect against.

We could all do with more of that. Lot’s of people like gaming so why not learn something useful at the same time as having fun? Let’s hope there are more fun, and commercial games, invented in future about cyber security. It would make a good cooperative game in the style of Pandemic perhaps, and there must be simple board game possibilities that would raise awareness oc cyber security threats. It would be great if one day such games could inspire more people to a career as a security expert. We certainly need lots more cybersecurity experts keeping us all safe.

– Paul Curzon, Queen Mary University of London

adapted from the archives

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Sea sounds sink ships

A shoal of silvery blue fish densely packed and swimming together
Shoal of fish in the Galapagos image by Christopher Chilton from Pixabay

You might think that under the sea things are nice and quiet, but something fishy is going on down there. Our oceans are filled with natural noise. This is called ambient noise and comes from lots of different sources: from the sound of winds blowing waves on the surface, rain, distant ships and even underwater volcanoes. For undersea marine life that relies on sonar or other acoustic ways to communicate and navigate all the extra ocean noise pollution that human activities, such as undersea mining and powerful ships sonars, have caused, is an increasing problem. But it’s not only the marine life that is affected by the levels of sea sounds, submarines also need to know something about all that ambient noise.

In the early 1900s the aptly named ‘Submarine signal company’ made their living by installing undersea bells near lighthouses. The sound of these bells were a warning to mariners about the impending navigation hazards: an auditory version of the lighthouse light.

The Second World War led to scientists taking undersea ambient noise more seriously as they developed deadly acoustic mines. These are explosive mines triggered by the sound of a passing ship. To make the acoustic trigger work reliably the scientists needed to measure ambient sound, or the mines would explode while simply floating in the water. Measurements of sound frequencies were taken in harbours and coastal waters, and from these a mathematical formula was computed that gave them the ‘Knudsen curves’. Named after the scientist who led the research these curves showed how undersea sound frequencies varies with surface wind speed and wave height. They allowed the acoustic triggers to be set to make the mines most effective.

– Peter McOwan, Queen Mary University of London

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Was the first computer a ‘Bombe’?

Image from a set of wartime photos of GC&CS at Bletchley Park, Public domain, via Wikimedia Commons

A group of enthusiasts at Bletchley Park, the top secret wartime codebreaking base, rebuilt a primitive computing device used in the Second World War to help the Allies listen in on U-boat conversations. It was called ‘the Bombe’. Professor Nigel Smart, now at KU Leuven and an expert on cryptography, tells us more.

So What’s all this fuss about building “A Bombe”? What’s a Bombe?

The Bombe didn’t help win the war destructively like its explosive name-sakes but using intelligence. It was designed to find the passwords or ‘keys’ into the secret codes of ‘Enigma’: the famous encryption machine used both by the German army in the field and to communicate to U-Boats in the Atlantic. It effectively allowed the English to listen in to the German’s secret communications.

A Bombe is an electro-mechanical special purpose computing device. ‘Electro-mechanical’ because it works using both mechanics and electricity. It works by passing electricity through a circuit. The precise circuit that is used is modified mechanically on each step of the machine by drums that rotate. It used a set of rotating drums to mirror the way the Enigma machine used a set of discs which rotated when each letter was encrypted. The Bombe is a ‘special purpose’ computing device rather than a ‘general purpose’ computer because it can’t be used to solve any other problem than the one it was designed for.

Why Bombe?

There are many explanations of why it’s called a ‘Bombe’. The most popular is that it is named after an earlier, but unrelated, machine built by the Polish to help break Enigma called the Bomba. The Bomba was also an electro-mechanical machine and was called that because as it ran it made a ticking sound, rather like a clock-based fuse on an exploding bomb.

What problem did it solve?

The Enigma machine used a different main key, or password, every day. It was then altered slightly for each message by a small indicator sent at the beginning of each message. The goal of the codebreakers at Bletchley Park each day was to find the German key for that day. Once this was found it was easy to then decrypt all the day’s messages. The Bombe’s task was to find this day key. It was introduced when the procedures used by the Germans to operate the Enigma changed. This had meant that the existing techniques used by the Allies to break the Enigma codes could no longer be used. They could no longer crack the German codes fast enough by humans alone.

So how did it help?

The basic idea was that many messages sent would consist of some short piece of predictable text such as “The weather today will be….” Then using this guess for the message that was being encrypted the cryptographers would take each encrypted message in turn and decide whether it was likely that it could have been an encryption of the guessed message. The fact that the German army was trained to say and write “Heil Hitler” at any opportunity was a great help too!

The words “Heil, Hitler” help the German’s lose the war

If they found one that was a possible match they would analyze the message in more detail to produce a “menu”. A menu was just what computer scientists today call a ‘graph’. It is a set of nodes and edges, where the nodes are letters of the alphabet and the edges link the letters together a bit like the way a London tube map links stations (the nodes) by tube lines (the edges). If the graph had suitable mathematical properties that they checked for, then the codebreakers knew that the Bombe might be able to find the day key from the graph.

The menu, or graph, was then sent over to one of the Bombe’s. They were operated by a team of women – the World’s first team of computer operators. The operator programmed the Bombe by using wires to connect letters together on the Bombe according to the edges of the menu. The Bombe was then set running. Every so often it would stop and the operator would write down the possible day key which it had just found. Finally another group checked this possible day key to see if the Bombe had produced the correct one. Sometimes it had, sometimes not.

So was the Bombe a computer?

By a computer today we usually mean something which can do many things. The reason the computer is so powerful is that we can purchase one piece of equipment and then use this to run many applications and solve many problems. It would be a big problem if we needed to buy one machine to write letters, one machine to run a spreadsheet, one machine to play “Grand Theft Auto” and one machine to play “Solitaire”. So, in this sense the Bombe was not a computer. It could only solve one problem: cracking the Enigma keys.

Whilst the operator programmed the Bombe using the menu, they were not changing the basic operation of the machine. The programming of the Bombe is more like the data entry we do on modern computers.

Alan Turing who helped design the Bombe along with Gordon Welchman, is often called the father of the computer, but that’s not for his work on the Bombe. It’s for two other reasons. Firstly before the war he had the idea of a theoretical machine which could be programmed to solve any problem, just like our modern computers. Then, after the war he used the experience of working at Bletchley to help build some of the worlds first computers in the UK.

But wasn’t the first computer built at Bletchley?

Yes, Bletchley park did build the first computer as we would call it. This was a machine called Colossus. Colossus was used to break a different German encryption machine called the Lorenz cipher. The Colossus was a true computer as it could be used to not only break the Lorenz cipher, but it could also be used to solve a host of other problems. It also worked using digital data, namely the set of ones and zeros which modern computers now operate on.

– Nigel Smart, KU Leuven

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Film Futures: Tsotsi

A burnt out car
Image by Derek Sewell from Pixabay

Computer Scientists and digital artists are behind the fabulous special effects and computer generated imagery we see in today’s movies, but for a bit of fun, in this series, we look at how movie plots could change if they involved Computer Scientists. Here we look at an alternative version of the film Tsotsi.

***SPOILER ALERT***

The outstanding, and Oscar winning, film Tsotsi follows a week in the life of a ruthless Soweto township gang leader who calls himself Tsotsi (township slang for ‘thug’). Having clawed a feral existence together from childhood in extreme urban deprivation he has lost all compassion. After a violent car-jacking, he finds he has inadvertently kidnapped a baby. What follows, to the backing of raw “Kwaito” music, is his chance for redemption.

Introducing new technology does not
always have just the effect you intended …

Tsotsi: with computer science

In our computer science film future version the baby is still accidentally kidnapped, but luckily the baby has wealthy parents, so wasn’t born in the township and was chipped with a rice-sized device injected under the skin at birth. It both contains identity data and can be tracked for life using GPS technology. The police are waiting as Tsotsi arrives back at the township having followed his progress walking across the scrubland with the baby.

Tsotsi doesn’t get a chance to form a bond with the baby, so doesn’t have a life-changing experience. There is no opportunity for redemption. Instead on release from jail he continues on his violent crime spree with no sense of humanity whatsoever.

In real life…

In 2004 there was a proposal in Japan that children would be tagged in the way luggage is. Now it is a totally standard way of tracking goods as they are moved around warehouses, and as a way to detect goods being shoplifted too. After all if it is sensible to keep track of your suitcase in case it is lost, why wouldn’t you for your even more important child. Fear of a child going missing is one of the biggest nightmares of being a parent. Take your eyes off a toddler for a few seconds in a shop and they could be gone. Such proposals repeatedly surface and

various similar proposals have been suggested ever since. In 2010, for example, nursery school kids in Richmond California were for a while required to wear jumpers containing RFID tags, supposedly to protect them. By placing sensors in appropriate places the children’s movements could be tracked so if they left school they could quickly be found.

Of course, pet cats and dogs are often chipped with tags under their skin. So it has also been suggested that children be tagged in a similar way. Then they couldn’t remove whatever clothing contained the tag and disappear. Someone who had kidnapped them would of course cut it out as, for example, Aaron Cross in the Bourne Legacy has to do at one point. Not what you want to happen to your child!

In general, there is an outcry and such proposals are dropped. As it was pointed out at the time of the California version, an RFID tag is not actually a very secure solution, for example. There have been lots and lots of demonstrations of how such systems can be cracked (even at a distance). For example, the RFID tags used in US passports was cracked so that the passports could be copied at a distance. And if the system can be cracked, then bad actors can sit in a van outside a school, or follow them on a school trip and track those children. Not only does it undermine their privacy, it could put them in greater danger of the kind it was supposed to protect them from. Ahh, you might think, but if someone did kidnap a child then the chip would still show where they were! Except if they can be copied then a duplicate could be used to leave a virtual version of the child in the school where they should be.

Security and privacy matter, and cyber security solutions are NEVER as simple as they seem. There are so often unforseen consequences, and fixing one problem just opens up new ones. Utopias can sometimes be distopian.

– Paul Curzon, Queen Mary University of London (extended from the archive version)

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Torchwood: in need of some backup

Multiple floors of an abandoned building
Image by Peter H from Pixabay

***SPOILER ALERT***

Disaster planning, that’s the Torchwood game. They are there to save the Earth whenever it needs saving from aliens (which is every week). Shame they blew it when it came to disaster planning for Torchwood itself!

We are coming

Torchwood is the BBC’s cult spin-off from Doctor Who. In the series, Children of the Earth, the world is threatened by the mysterious and brutal ‘456’ whose arrival is heralded when every child in the world simultaneously stops in their tracks and chants ‘We are coming’. The Torchwood team of Captain Jack Harkness, Gwen Cooper and Ianto Jones once more spring into action. Unfortunately, early on a little accident (we won’t say what so as not to spoil it) happens in their base buried under Cardiff. On the run and homeless for a while, they have only their wits in place of the normal hi-tech surveillance gadgetry. It’s so desperate at one point, they end up in an empty shell of a warehouse with only a sofa and the contents of their pockets with which to save the world!

Move it!

It’s such a shame that it comes to this when a little bit of disaster planning would have made it all so much easier to beat the aliens. A backup plan including a backup site is crucial in dealing with a disaster, whether earthquake or Martian hordes. Just because your home city has been hit by a tsunami or flattened to the ground by a meteorite doesn’t mean your company’s operations have to be disrupted.

Captain Jack knows all about disaster management of course. Kill him, and after a brief period of pain he jolts back to life and carries on as though nothing has happened. With some standard forward planning any organisation ought to operate just like that too.

The fact that when the disaster happens the Torchwood team have to come up with solutions on the fly shows that they not only had no backup, but hadn’t even thought about it. Tut tut!

If they had done some planning, what would have been their alternatives?

Cold war

The first alternative, for those organisations that need to survive a disaster is to have a ‘cold site’ ready. In fact this is what Torchwood defaulted to in their warehouse. Lucky Ianto remembered it! A cold site is just a backup location that can be moved in to. It doesn’t have software, data or even hardware ready, but at least everyone knows what to do and where to go. In time it can be up and running again. Clearly given their remit of saving the Earth against war-hungry aliens, Torchwood needed something better than that.

Getting warmer

At the other end of the disaster planning spectrum is the ‘hot site’. It is a fully functioning copy of your main operations building. All the hardware is there, the software is there and so is the data. Everything that happens at the main site IT-wise is copied at the hot site too. Lose your main site to a nuclear bomb and you just carry on almost seamlessly at the hot site. (It obviously has to be located somewhere else suitably far away, not just next door, or it too will be as radioactively hot as the original and be of little use). You can also have ‘warm sites’ of different degrees where for example you just have the hardware installed, or the data backups are only weekly rather than continuously.

Which kind of backup site is chosen depends on the organisation: what can it afford balanced against the costs of downtime (and how much down time the business can take and still survive). If it is critical to the survival of the planet, like Torchwood, then clearly you need to be at the warmer end of the backup scale!

Back to life

It’s a shame then that Torchwood’s IT management only focused on installing lots of fancy gadgets and ignored the more mundane side of things. If they had been a little more competent Jack and co might have sorted out the ‘456’ before it all got out of hand. Never mind. It all worked out OK in the end. Well, sort of.

– Paul Curzon, Queen Mary University of London (from the archive)

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