Thursday, 7 May 2015

Politics for the Simple

Naomi's been asking about the election, so I've been trying to explain to a three-year-old, in as unbiased a way as I can, who the main candidates are and why they want to be in charge. If you're not sure how to vote, this might help you too.


For the last little while, Dave has been in charge of the country, with a bit of help from Nick.

Dave says he's been quite good at being in charge and would like to keep doing it for a bit longer. He thinks Ed would muck it up.

Ed says that it's his turn to be in charge now, and that Dave has mucked up quite a lot of things.

Nick says he doesn't really mind who's in charge, as long as he's allowed to join in too.

Friday, 25 October 2013

Triple equivocation: when three wrongs make a right

You've presumably noticed that some people talk obvious drivel. They're not usually much trouble: obvious drivel is easy to refute (or just ignore). What's harder to deal with is people who talk plausible-sounding rubbish: arguments that you know must be wrong somehow, but you just can't see how. For instance:

Philosophers have various names for the different types of fallacious reasoning; they're useful to know about because they can help you spot where an argument has gone wrong. One of the subtlest types of fallacy is called equivocation; this involves using the same word in two different senses, to construct something that looks like good reasoning but is in fact nonsense. Here's a classic example:
  1. A hot dog is better than nothing.
  2. Nothing is better than a nice, juicy steak.
  3. Therefore, a hot dog is better than a nice, juicy steak
What's gone wrong here? The word nothing has been used in two different ways. In (1), it means nothing at all, whereas in (2), it means no possible food. So although each premise is (arguably) correct, and the argument looks valid, the conclusion is false.

The nicest example I have seen is the one William Lane Craig uses to explain equivocation:
  1. Socrates is Greek.
  2. Greek is a language.
  3. Therefore, Socrates is a language.
The word Greek has been used in two different senses here: in the first premise, it's a nationality, and in the second it's a natural language. So, again, two true premises but a seemingly obviously false conclusion.

Now that all seems plain enough. But here's the shock: Socrates, contrary to all expectation, is, in fact, a language. I stumbled across a web site the other day that describes Socrates as "[a] programming language embedded in PLT Scheme that supports advanced separation of concerns using predicate dispatching".

This puts the example in a completely new light. We thought we had a false conclusion because of equivocation on the word Greek; it now turns out that Socrates means two different things here (a philosopher and a programming language); and language is also being used in two different ways (a natural language and a programming language).

So we have two true premises; a true conclusion; and a triple equivocation, on Greek, Socrates and language.

Sometimes, it seems, three wrongs do make a right. Who'd have thought it?

Sunday, 23 June 2013

The Eggy Mattress Puzzle

Excellent little puzzle from Puzzle Man Dave.

You're standing outside a 120-storey building, which has a mattress on the ground outside it. You have two identical eggs; and what you want to know (for no doubt excellent, but irrelevant, reasons) is the highest floor at which you can drop an egg out of the window and have it land on the mattress without breaking. You don't mind getting your mattress a bit eggy in the process, but you need a way of guaranteeing to find the highest floor.

Obviously even if you just had one egg then you could still find out the answer: you'd drop it out of the first floor, and if it didn't break, then you'd go for the second floor, and then the third, until it smashed. That would be the only procedure that would guarantee to discover the answer: if you started by dropping it out of floor five, for instance, and it broke, you'd have no idea whether it would have broken from floor four, and you'd be out of eggs. It works, but in the worst case it takes 120 drops.

But if you have two eggs, you can do better than that. You can guarantee to find out the answer in many fewer than 120 drops.

What's the optimal method, the one that guarantees to find the highest floor at which an egg won't break, but minimizes the number of drops required in the worst case?

Wednesday, 4 January 2012

Name The Baby Competition!

On reflection, that seems pointless. Who wants to name a baby competition? Let's just call it The Baby Competition.

The essence of what's already become known as The Baby Competition is that one lucky reader will get to name the baby when it pops out next May. Below is our shortlist; feel free to add your own suggestions. Here's a picture from today's scan to help the mulling process.

The foetus gets beamed up by aliens

Add your chosen name to the comments box below. After the birth, we'll scribble all the names onto pieces of paper and put them into a Moses basket, and get the baby to pull one out. Whoever's name gets picked will win a free umbilical cord and a half hour swim in the birthing pool.

Boys' names Girls' names
Engelbert Humpyheather Rihanna R. Riheather
Mohammed Mohammed
Sir Harry Pearce Abigail Downtonia
Willsnkate Pippabottomarse
Rumpelstiltskin Rapunzel
Terry Tearaway Mrs Goggins
Mummy's Little Soldier Daddy's Little Princess
Beowulf Boadicea
Dawkins Mrs Gren
Baby Bublé Baby Gaga

Wednesday, 14 September 2011

Oh, how I love selected parts of your law!

All Scripture is God-breathed and is useful for teaching [...] I give you this charge: Preach the Word.
—2 Timothy 3:16–4:2
When was the last time you heard a sermon on Zephaniah? Or Philemon? How about the second half of Daniel?

We pay lip service to the inspiration of the whole of Scripture, but I wonder whether we really believe it. Do we use the whole Bible, or do we just pick out the bits we like? One way of gauging this is to look at what passages we preach on: if we take seriously our charge to use all of Scripture for teaching, then you would expect to find that, over time, our sermon texts would bear that out. We should probably not expect a completely flat distribution: it is perhaps reasonable to expect sermons to cover the gospels more often than Leviticus, since the gospels more clearly and directly reveal Jesus. But if we believe that all Scripture is God-breathed, then we should not expect to find that some parts of the Bible receive all our attention and some are essentially ignored.

Finding good aggregated statistics on what is preached in churches around the world is difficult, simply because churches don't publish their sermon plans in any systematic fashion. But there are ways of getting a useful indication.

The Gospel Coalition web site is an excellent resource for finding, among other things, sermons preached in evangelical churches worldwide. I use it all the time, and I have found it invaluable. As of September 2011, it lists around 34,000 sermons, most of which can be downloaded and listened to. That is a vast number—more than there are verses in the whole Bible. It also acquires its material from a large number of churches and an even larger number of preachers, and thus one would expect it to be representative of the state of evangelical Christendom as a whole, and not susceptible to the biases and tendencies of one particular church or minister.

So what does its database reveal?

Below is a Wordle, showing how often each book of the Bible is represented in the database. The size of the font is proportional to the number of sermons taking its primary text from that particular book.

What do we preach on? (PDF)

The image is quite striking. The New Testament dominates to a remarkable extent: only Genesis and the Psalms can compete, and even they are some way down the list. The minor prophets are almost non-existent.

But there are other points of interest. It is perhaps not surprising that we spend most of our time in the gospels; but notice how far behind the rest Mark lags. And who would have expected such a difference between Ephesians and Colossians?

Of course, some books are much longer than others. One would not expect a series on 2 Thessalonians to contain as many sermons as a series on Exodus, simply because there is less material to cover. A sermon series that went through the entire canon at the rate of one chapter per week would quite sensibly spend one week on Obadiah and nearly three years on the Psalms. So perhaps we should weight the entries according to the length of each book.

This second Wordle does just that. Each book is weighted by taking the number of sermons on that book in the database divided by the number of words in the book (in an English translation). This should have the effect of controlling for book length: if books were favoured simply according to their lengths, the Wordle would have all entries in the same size font.

Taking book length into account (PDF)
Notice what has changed and what has not. The Old Testament is still largely absent, and has faded even more now that Genesis and the Psalms, two of the longest books in the Bible, have all but disappeared (see if you can spot them). Jonah is the only one that catches the eye.

But what has happened to the gospels? Mark is now able to keep pace with the other gospel writers—perhaps we soft-pedal him only because his gospel is shorter than the others—but all four have been left in the shade. Word for word, we spend far longer on the epistles (which now dominate the image) than we do on the gospels.

What about choice of passage within a book? Do we demonstrate there that we believe the whole book is inspired, or do we cherry-pick the "good" bits?

This graph shows, for each chapter of Isaiah, how many sermons there are in the Gospel Coalition database taking that chapter as the primary text.

The keen-eyed will observe that the graph is not flat. Some chapters receive significant attention, whereas others are passed over. Three chapters, in fact, have no sermons on them. The six most famous chapters in Isaiah are probably chapter 1 ("Though your sins are like scarlet..."), chapter 6 ("In the year that King Uzziah died..."), chapter 9 ("To us a child is born..."), chapter 40 ("Comfort, comfort my people..."), chapter 53 ("He was pierced for our transgressions..."), and chapter 55 ("Come, all you who are thirsty..."). These chapters are represented by the six biggest peaks in the graph; and on average, there are 50.2 sermons for each of these six chapters. For the rest of Isaiah, there are 6.8 sermons per chapter.

Isaiah is not the only book to show wildly uneven treatment. There are 106 sermons on Psalm 1; sixteen Psalms are covered in only one sermon, and Psalms 64 and 70 have no hits at all. There are 199 sermons on Acts 2 (Pentecost) and 24 on Acts 12 (Peter's escape from prison).

It would be easy to make too much of this. There may be any number of reasons for some of these effects. For instance, any responsible sermon series that goes through Isaiah must take in Isaiah's commission in chapter 6; and it would be unreasonable to expect every series to cover every chapter. So it is unsurprising that chapter 6 gets more hits than any other. And there is good reason for giving greater prominence to the clearer parts of Scripture, so it may well be appropriate for Ephesians to receive more air time than Ecclesiastes. Perhaps 2 Chronicles receives less attention because it duplicates much of the material in 2 Kings.

But I am not convinced that all of it can be explained in such terms. What is striking is not that the distribution is uneven, but that the unevenness is so stark. It surely cannot be right that you are over 13 times as likely to hear an exposition of Matthew 5 (the start of the Sermon on the Mount) than of Matthew 19 (divorce). One can hardly make out that divorce is pastorally irrelevant today.

So why is this happening? Let me suggest three reasons.

For one, familiar bits of Scripture are easier to understand. Preaching on a text involves understanding it in its context; that, of course, is much easier to do if you already know the context. So whilst preaching on Ephesians 2 might involve some wrestling with the text to understand the finer points, it is unlikely to require significant blood, toil, tears and sweat to come to terms with the overall message of Ephesians. But now imagine that you have been asked to preach on Nahum 2. You have a good deal of work ahead of you before you start trying to unpack chapter 2. Who was Nahum? Northern kingdom or southern kingdom? What time period? Who were his primary audience? Can I even find Nahum without looking in the index?

Secondly, for exactly the same reasons, familiar bits of Scripture are easier to explain. A typical church will not need reminding every week that Acts details the growth of the early church after Jesus' ascension. But start a series on Ezekiel, and you have a lot of historical background to fill in before you can get to the text itself.

Thirdly, familiar bits of Scripture are easier to preach without rocking the boat. Honestly, who wants to preach on divorce? Or hell? Or the Canaanite genocide? Much easier to tackle something light and fluffy. The last thing you want to do is to raise difficult pastoral issues.

This is a dangerous game to play. The clear message we give off is that most of Scripture is theoretically inspired but not really worth bothering with. Zephaniah simply has nothing to say to us. Titus is boring. Matthew's worth preaching on, but do skip the tricky bits.

Man does not live on bread alone but on every word that comes from the mouth of the Lord.
—Deuteronomy 8:3

Do we really live on every word? Or do we eat the middle and leave the crusts? Stop playing with your dinner and eat it properly.

Sunday, 14 August 2011

Post-Camp Blues: be careful, it's boring out there...

Yesterday, I came back from what I think is my 25th CYFA camp! I've now spent a total of more than six months on camp.

The first time I went, I was pretty nervous about it. I didn't know what to expect, and I didn't know whether I'd manage to make friends with anyone. But it didn't take long for that to pass. Now, some of my best friends are people I met on camp, and some of the others (including my wife) are people I met in a roundabout way via camp. God has also taught me, through camp, more than I can ever remember to thank him for. And he has granted me the wonderful privilege of serving him through chatting with people, praying with people, washing up, and pouring buckets of water on people's heads. Blessings all mine, and ten thousand beside.

Going to camp is now easy, and something I spend 51 weeks of the year looking forward to. What is much more difficult is coming home afterwards. On camp, you can feel close to God and close to others, and there's no time to catch your breath, let alone get stuck for things to do. But suddenly you're at home, and you remember how boring the real world is. Where did God go? Where did my friends go? What am I going to do for the next 51 weeks?

Post-camp blues is something that members, helpers, leaders and cooks all go through, and I don't have an easy answer. I think that when I find coming home from camp easy, that's when I'll know it's time to stop going. But there are some things you can do to make it at least not quite so horrible.

Remember what God has done

I cried out to God for help; I cried out to God to hear me. I thought about the former days, the years of long ago; I remembered my songs in the night. My heart mused and my spirit enquired: "Will the Lord reject for ever? Will he never show his favour again? Has his unfailing love vanished for ever? Has his promise failed for all time? Has God forgotten to be merciful? Has he in anger withheld his compassion?" Then I thought, "To this I will appeal: the years of the right hand of the Most High." I will remember the deeds of the Lord; yes, I will remember your miracles of long ago. I will meditate on all your works and consider all your mighty deeds. (Psalm 77:1, 5–12)

We tend to think of bible times as being an endless flow of drama and miracle, as though every moment were an exciting demonstration of God's presence and power. But, of course, it wasn't like that at all. The bible covers thousands of years of history, and most people's lives, most of the time, would have been quite ordinary.

The Israelites had the same temptation as we do: to forget what God had done for them. They constantly needed reminding to look back at how God had been faithful in the past so that they would trust that God would remain faithful in the future.

Coming back from camp can leave us so flat, and can leave God seeming so distant, that we quickly forget the blessings God rained down on us at camp. We start to wonder where God is. "Will he never show his favour again? Has his unfailing love vanished for ever?"

We need to be taught to remember what God has done, both in history in sending Jesus, and in our own lifetime in the ways he has drawn close to us on camp and elsewhere. Meditate on how God has blessed you in the past, and use that to help you trust him for the future.

Anchor yourself in Jesus' blood, not your own feelings

When I see the blood, I will pass over you. (Exodus 12:13)

There are so many things on camp that can give you a sort of spiritual buzz. It is so uplifting to hear an inspirational talk, or sit around a camp fire late at night singing "In Christ Alone" with fifty of your friends. These are all good, and God works through them to build us up and bring us closer to him. But they also have a significant danger: we can start to base our faith and our confidence on our own feelings. And when we come home and the feelings disappear, we start to question whether we're really Christians, or whether God really loves us. Feelings come and go; and if your confidence in God's love is based on feelings, it will come and go too.

When the Israelites came out of slavery in Egypt under Moses, they were told to kill a lamb and spread the blood on their doorposts. God was going to come through the land that night and bring judgement on the Egyptians by killing the firstborn son in every house. But for the Israelites, the lamb would be a substitute: God would see the blood of the lamb on the doorposts, and pass over without killing the firstborn son.

I should imagine that many of the Israelites were very scared that night. They had seen enough of God's judgement to know that it was real. What if they didn't believe strongly enough? What if they didn't feel close enough to God? What if their faith let them down, and God brought judgement on them during the night?

But what saved the Israelites from judgement was nothing to do with their feelings. What saved them was not the strength of their faith but what their faith was based on: God had promised that he would pass over when he saw the blood. However scared they might have been, however faithless, God was faithful to his promise.

So with us. We are saved because God sees Jesus' blood and passes over. Our salvation is not grounded in the strength of our feelings but in the death of Jesus, our Passover lamb and our substitute.

Get involved with others around you

"You will all fall away," Jesus told them, "for it is written: 'I will strike the shepherd, and the sheep will be scattered.' But after I have risen, I will go ahead of you into Galilee." Peter declared, "Even if all fall away, I will not." "I tell you the truth," Jesus answered, "today—yes, tonight—before the cock crows twice you yourself will disown me three times." But Peter insisted emphatically, "Even if I have to die with you, I will never disown you." (Mark 14:27–30)
Peter began to call down curses on himself, and he swore to them, "I don't know this man you're talking about." Immediately the cock crowed the second time. Then Peter remembered the word Jesus had spoken to him: "Before the cock crows twice you will disown me three times." And he broke down and wept. (Mark 14:71–72)

Part of what makes coming home so difficult is that we've been surrounded by other people for a whole week. There's always someone to talk to on camp. You come back, and suddenly you're on your own. The love and support you enjoyed so much is whipped away from under you, and it can be a very lonely place to be. The temptation then is to grit your teeth and tell yourself you'll get through the next couple of weeks on your own by sheer willpower: "Even if all fall away, I will not." Peter tried that; it didn't work.

The bible never teaches us to go it alone. God made us to relate to one another, and to love, encourage and support one another. Jesus did not die to make you an individual Christian, but to make you part of his body. You won't survive apart from the rest of the body; you weren't designed to do so.

There isn't anything quite like camp for mutual encouragement. But unless you live on a desert island, there are other Christians near where you live who are important for your sanity and your continued growth. Get stuck into a church. Go to a youth group. Ring your friends and tell them what you learnt on camp.

Focus on God's word

These commandments that I give you today are to be upon your hearts. Impress them on your children. Talk about them when you sit at home and when you walk along the road, when you lie down and when you get up. Tie them as symbols on your hands and bind them on your foreheads. Write them on the door-frames of your houses and on your gates. (Deuteronomy 6:6–9)

A week of reading the bible together is brilliant, but it's not supposed to stop there.

Moses didn't teach the Israelites to have a quiet time, as though they should spend ten minutes each day thinking about God and then forget his word for the rest of the day. Moses taught them to saturate themselves with Scripture. God's word was to be in their hearts, not on their smartphones. It was to be their chief topic of conversation at breakfast, lunch and dinner, in the car, at school, and throughout the day. They were to superglue it to their hands and nail it to their heads. They were to scribble verses on their bedroom walls, and chisel them into their front doors.

Make it your business this week, this month, this year, to read your bible till it falls apart. If you're not sure where to start, try Mark's gospel, and then the letter to the Colossians. If you're not sure how to read your bible, ask your dorm leader to send you some bible reading notes. If you'd like to get some yourself, you might like to try the Explore series. For something more crunchy that will take you through the bible in a year, get hold of Don Carson's For The Love Of God.

And never decide not to read your bible because you've "done your quiet time today". I promise you, the more you read it, the more you will learn to enjoy reading it. Talk to your friends and family about it. Meditate on it day and night. Write it up and down the road in alphabetti spaghetti. Nourish yourself from the food that God has given you.

Be careful to follow every command I am giving you today, so that you may live and increase and may enter and possess the land that the Lord promised on oath to your forefathers. Remember how the Lord your God led you all the way in the desert these forty years, to humble you and to test you in order to know what was in your heart, whether or not you would keep his commands. He humbled you, causing you to hunger and then feeding you with manna, which neither you nor your fathers had known, to teach you that man does not live on bread alone but on every word that comes from the mouth of the Lord. Your clothes did not wear out and your feet did not swell during these forty years. Know then in your heart that as a man disciplines his son, so the Lord your God disciplines you. Observe the commands of the Lord your God, walking in his ways and revering him. For the Lord your God is bringing you into a good land—a land with streams and pools of water, with springs flowing in the valleys and hills; a land with wheat and barley, vines and fig-trees, pomegranates, olive oil and honey; a land where bread will not be scarce and you will lack nothing; a land where the rocks are iron and you can dig copper out of the hills. When you have eaten and are satisfied, praise the Lord your God for the good land he has given you. Be careful that you do not forget the Lord your God, failing to observe his commands, his laws and his decrees that I am giving you this day. (Deuteronomy 8:1–11)

Thursday, 7 July 2011

Heatherweight Encryption: Provably Brilliant Crypto

James Heather (No Institute Given**)

[This is the complete text of a paper to appear in due course in the highly esteemed Journal of Craptology.]

Abstract. Most fashionable cryptosystems suffer from many drawbacks: they produce inefficiently long ciphertexts, they take a tediously long time to perform their basic operations, and they are vulnerable to any number of troubling attacks. In this paper, we1 propose a cryptosystem that excels in every respect. We give proofs of optimality of security, algorithmic complexity, and ciphertext size.

1 Introduction

The world has long suffered under the weight of such behemoths as RSA, ElGamal, the so-called ‘Advanced’ Encryption Standard, the so-called ‘Secure’ Hashing Algorithm2, and that one where you wrap a strip of paper round a pencil. Every one of these is so inefficient as to be amusing. They take far too long to encrypt, produce ciphertexts that are big and unwieldy, and can be cracked with minimal effort. A small personal case study will serve to illustrate.

Mr Fardoso on his way to the bank
Last year I received an email from Mr Daniel Fardoso, the terminally ill nephew of a deceased Nigerian diplomat, who needed my help in shifting a large quantity of money so that he could live out his remaining months in peace and comfort. Modesty forbids recounting the many reasons that Daniel gave for choosing me to entrust with this task; suffice it to say that he seemed to have every confidence that I had the qualities he was looking for. He asked me to fill in a simple and supposedly secure web page with my bank details, my mother’s maiden name, my passport number, and my name and address. Naturally, I concurred; and, when I clicked on the ‘Submit’ button, a window appeared telling me that it was encrypting the file for safe transmission to Daniel.

Until that point, I had expected that modern cryptographic methods would work securely and efficiently. Much to my disappointment, it was still encrypting the file some three hours later when I retired for the night. In the morning, on discovering that the encryption still had not finished, I sent Daniel an email expressing my concern; he reassured me that there was no sign of any problem at his end.

You can imagine my shock when I received a phone call from the police that afternoon, informing me that £35,000 had been cleaned out of my account! It distresses me to say that they tried to blame first Daniel, and then me, for the security breach. My complaint that I had taken every precaution to encrypt the file securely fell on deaf ears.

So much, then, for current encryption systems! Two honest, law-abiding citizens attempt a supposedly secure transaction, and the hackers take full advantage. One cannot help concluding that if the encryption had been faster, then Daniel and I might have had time to stop the theft; and if it had been more secure, then the hackers would not have been able to break it in the first place.

2 Analysis of current systems

Figure 1 gives more technical insight into the inadequacy of currently available cryptosystems.

Figure 1: RSAges-to-encrypt

The graph is self-explanatory. Small wonder that hackers are winning the battle against security experts, the banking system is in crisis, teenagers lurk around every corner drinking Hooch and smirking, and I wake up screaming in the night, scared of my own hands. A radical new approach is needed.

This paper solves all these problems. It is no exaggeration to say that the encryption algorithm proposed here does for cryptography what Isaac Newton did for physics, what Alexander Fleming did for medicine, and what Monica Lewinsky did for Bill Clinton.

3 Heatherweight encryption

We have seen that existing algorithms are both heavyweight and cumbersome. In this section, we give the details of Heatherweight3 encryption, a simple and yet effective reinvention of the field.

The encryption algorithm is perhaps the simplest algorithm one could ask for. To encrypt a message m using key K, we calculate
EK(m) = <>

In other words, the ciphertext is the zero-length bitstring.

4 Proofs of optimality

We now give proofs that Heatherweight encryption is optimal in terms of ciphertext length, algorithmic complexity of the basic operations, and security.

Theorem 1 (Optimality of length of ciphertext): Heatherweight encryption produces ciphertexts that are of optimal size for data transmission and data storage.

The whole Internet, safely encrypted
Proof. Ciphertexts are zero length, regardless of the length of the input message. This means that the encryption also provides a level of compression that would make Huffman weep horrible tears. Any number of ciphertexts can be transmitted in zero time, and can be archived on even limited capacity storage media without using up any space. Using Heatherweight encryption, one can compress the whole of the Internet, and scribble the resulting ciphertext in full on the back of an envelope—without even needing a pen!

Theorem 2 (Optimality of algorithmic complexity): Heatherweight encryption and decryption are optimal in their time complexity.

Proof. It has long been assumed that the very best one might hope for, in terms of time complexity of encryption and decryption, is linear, simply because the algorithm needs to examine the whole plaintext to construct the ciphertext. However, the genius of Heatherweight encryption is that it produces ciphertexts that are independent of the plaintext. Encryption can therefore be done in constant time:
public byte[] encrypt(byte[] key, byte[] plaintext) {
    return new byte[]();

But what about decryption? It is obvious that for many encryption systems, the main security weakness is the decryption algorithm. Sometimes this is because of a flaw in the algorithm itself that allows an attacker to break the ciphertext without needing the key; but there are also timing attacks and suchlike to consider. Even in the absence of these tactics, there is still the possibility that the key will leak, or that the keyholder will be tortured and forced to send the key to the attacker along a rubber hose.

Heatherweight encryption solves these problems by simply not providing a decryption algorithm. Security is considerably tightened by this technique, as we shall see.

This means that decryption can also be considered a constant-time operation:

public byte[] decrypt(byte[] key, byte[] ciphertext) {
    throw new OperationNotSupportedException("meh");

Theorem 3 (Perfect security): Heatherweight encryption provides perfect security.

Proof. An attacker with access to a decryption oracle is unable to distinguish between EK(m1) and EK(m2), because all encryptions are the same, so it is impossible to distinguish anything at all. Note that we have not reduced this simply to an underlying hard problem, but to an impossibility.

This even thwarts a 24 attack. Normally Jack is able to beat the decryption key out of anyone, and Chloë can crack any encryption, though usually not until 23:59:57. However, with Heatherweight encryption, even if Jack makes me send him the key down the rubber hose, and Jack then sends it through the hose to Chloë, she is not going to be able to get anything other than OperationNotSupported exceptions.

5 Conclusion

Heatherweight encryption changes everything. Just as everyone remembers where they were when they heard that JFK had landed on the moon, so everyone will remember the day when they entrusted all their backups to the power of Heatherweight encryption.

6 Future work

Almost too good to be true
Research is already underway to construct a hash function based on Heatherweight encryption. I conjecture that the Heatherweight encryption algorithm itself could be used directly as a constant-time hash function; but I need to spend some time convincing myself that it would be collision resistant.

Infinite-capacity hard drives with transparent Heatherweight encryption will soon be available. A prototype is already in existence; write speeds are nothing short of phenomenal, though we are having teething trouble with the read operation, which for some reason keeps throwing OperationNotSupported exceptions. An investigation is underway.


The author is grateful to Antonio Banderas for inspiration. It was while watching his performance as Zorro that the zero function first surfaced as an idea for an encryption algorithm. Previous meditations on his co-star had led to consideration of the zeta function ζ(s) = Σ 1/ns, which did not work nearly so well.


**The University of Surrey’s legal team has formally requested that this work be submitted in a purely personal capacity.

1I use the royal ‘we’, but the sad fact is that I was unable to persuade anyone to act as co-author. My initial aim was to break the world record for the number of authors on an academic paper, but, owing to what must be considered a terrible short-sightedness on the part of the eighty or ninety people I approached (including my own mother), the current record must stand.

2SHA is currently on its 256th version! The first 255 versions go belly up, and they expect us to take SHA256 seriously!

3I am indebted to Peter Ryan for the name ‘Heatherweight’. Nonetheless, the University of Luxembourg’s legal team has asked me to clarify that ‘this does not reflect recommendation or endorsement of any of the rather confused ideas represented in this paper’. One is reminded of Decca Records’ decision in January 1962 not to offer the Beatles a recording contract.