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I happen to know the author of this. This was a really tough thing for him to read, but he's taking it as constructive criticism.

I would add to the people commentating here on HN: tptacek's review is tough; you do not need to lay into the author of this book any more.

It's a tough thing for anyone to read: it's browserWidth wide and monospaced.

Here's a readable version: https://gist.github.com/mikemaccana/10847077

it's browserWidth wide

I like that, because my browser window is resizable.

I don't. So is mine, but resizing it for each individual website is unnecessary work. And some websites have a legitimate need for a wider format, so you can't even say "all websites should be like this".

I think the tone is what makes it tougher than it needs to be, not the factual content. Props to the author for just looking at the content and not at the way in which it was delivered. Props to Thomas for taking the time to review the book.

You're being downvoted, but I agree that a greater amount of tact would have been warranted. Phrases like "I am not making this up", "argh!" and "huh?" add nothing to the review, but only serve to make it more personal, and I say this as a guy who also has very little tact.

There has been a cultural shift in recent years. None of tptacek's observations are adhominem. But there is now an expectation that one tone down the description of one's own reaction. I suspect this is often a conflict between the expectations of the children of helicopter parents and my generation. (1)

Sorry, but I have a right to an emotional reaction to your content and a right to describe it, especially if the reaction is grounded in objective technical reality. I suspect that younger people have this idea that online descriptions of emotional reactions are fictional and purposely crafted for effect -- mostly having to do with emotional aggression. It's true that sometimes "passion" over a subject is used as a pretext for such aggression. That doesn't mean that it's always true, however. In some cases, it's honesty.

That said, "arrrgh" reactions in a technical discipline often indicate a frustrating failure of outreach, education, or communication. I learned things from reading tptacek's review. Maybe he could supervise the ghost-writing of his own undoubtedly excellent book?

(1) - I was riding the bus and this young man had his sneakers tied to the back of his backpack, the soles of which he was pressing into my chest. I tried discretely hinting to him by pressing back, but he was oblivious, so I brought this to his attention.

I was amazed that his first priority wasn't to apologize or help me out, rather it was that I recognize that he didn't mean any harm. Be correct first, then worry about your own ego second.

I would argue that it's not as simple as

> I have a right to an emotional reaction to your content and a right to describe it, especially if the reaction is grounded in objective technical reality

... because while you have rights, being a person who participates in a civilized society means you also have responsibilities, and one of those responsibilities is to interact with people in ways that are appropriate to the situation.

And "appropriate to the situation" changes depending on the nature of the situation. The less serious the situation, the less appropriate a volcanic reaction becomes. Nobody's going to disapprove of you if you start screaming at an airline pilot who you see snorting coke on his way to the plane. But lots of people will disapprove of you if you lay down the same reaction on some poor kid behind the counter at McDonald's because he forgot your French fries.

In the case of this review, I would say tptacek's tone is appropriate, because security is Serious Business (as we should all know, especially after last week); getting it wrong can result in people getting robbed or even killed. So if you're going to put yourself forward as a teacher of crypto, and you're teaching people things that aren't true, you're doing real damage and should be glad a good yelling-at is the worst punishment you have to suffer. But that doesn't mean that the same tone would be appropriate if taken with the kid on the bus, because "annoyingly oblivious" is a long chalk from "could get people killed."

I never said what my tone was on the bus -- it was blunt and matter of fact. My observation was about the young man's reaction. I take exception to your post, as it suggests I said something I didn't.

My point was more about the way you leapt from tptacek's review of the crypto book to the incident on the bus, which implies that they're comparable situations, when really they're not. Not all cluelessness is equal.

> I take exception to your post

I demand satisfaction! Pistols at dawn, my good fellow! Pistols at dawn!

My point was more about the way you leapt from tptacek's review of the crypto book to the incident on the bus, which implies that they're comparable situations, when really they're not.

Ugh. My point in the previous comment -- for the second time -- is not that I'm not comparing the situations. I'm comparing the reactions. Not all cluelessness is equal, and for the second time I never said that! However, oversensitivity to criticism due to a prioritization of feelings/ego generalizes nicely across both situations.

I demand satisfaction! Pistols at dawn, my good fellow! Pistols at dawn!

I only take challenges from people with basic literacy and reading comprehension. Your comments only demonstrate the former, my good fellow. (Or, if this is the 2nd iteration of a deliberate troll through the subtle placing of words in another's mouth, I'll merely comment that I'd be a bit surprised if someone actually thinks this is clever, and note that this would disqualify a challenger though insufficient intellectual integrity.)

You're spot on with the cultural shift.

To me, complaints about tone are for critiques that contain phrases like "fucking idiot" and "worthless waste of space" and other such direct insults or attacks.

If something legitimately makes you stop and stare with your mouth hanging open, it is OK to say "this statement made me stop and stare with my mouth hanging open." Phrases like "I am not making this up" are reasonable shortcuts to expressing that sentiment.

Could Mr. Ptacek's review have been worded more kindly? Of course. Do I care? Not at all. It was nice enough. It concentrated on technical flaws rather than personal attacks. It was informative and useful. The tone was just fine.

> If something legitimately makes you stop and stare with your mouth hanging open, it is OK to say "this statement made me stop and stare with my mouth hanging open."

It's okay if you are writing a story about your personal reactions.

It's irrelevant if you are writing a serious critique, which should be about the content, not about your emotional response to it (assuming it is a critique of an informative work -- obviously, if you are critiquing something as a work of art intended to inspire emotional responses, writing about your response as some relevance.)

It's possible to blend the first kind of story with the second kind of critique, but you have to recognize the different roles of each, do it deliberately, and be exceptionally skilled (the set of people who can do this and produce something worth reading is a proper subset of the intersection of the sets of those who can write entertaining personal stories and those who can write valuable straight critiques.)

That being said, tptacek's review seems pretty focussed on substantive critique with very minimal emotional distractions, so while I disagree with the categorical defense of the individual statements at issue as being appropriate to a straight critique of an informative work, I also think that the charge that the tone was inappropriate and a barrier to reading is overblown considering the fairly minimal level at which distracting emotional descriptions are present in the review.

Sure, it's irrelevant. It adds some color, but it's unnecessary. But who cares? The complaints are not "this writing could be tighter, it wastes words on unnecessary side notes." They are, "oh my god you're hurting this poor fellow's self esteem with your tone!"

It's ironic that these critiques of this review are much dumber than the review's critiques of the book, and implicitly hold a fairly off-the-cuff internet comment to far higher standards than a published book that purports to give important and useful advice about cryptography.

Could this review be better? Sure. But who cares?

Out of curiosity, how could it have been better?

There isn't a whole lot. I think removing some of the emotional language would help. I prefer my technical articles to be a "just the facts, ma'am" and make an effort to write that way myself. I think it could also have benefitted from some additional explanation of the right way, beyond just pointing out the wrong way. For example, I would love to have seen a brief explanation of why hash functions aren't MACs, and why MAC-then-encrypt is the wrong way to do things. I already have a basic familiarity with that (at least partially from some of your previous comments), but I'm sure your explanation would at the very least help cement the ideas in my mind, and probably teach me something new.

That said, I want to point out that I think your review was excellent and it's the kind of thing I love coming across. It many ways, it reminds me of the heyday of Usenet. It's great content and it doesn't need to be better. To the extent that it can be better, it's because nearly any work can be made better with additional effort.

Personally I like the emotional language, because it lets someone slightly less familiar with the field get a sense of how bad each thing is.

A purely "just the facts" version might need a "how bad on a scale of 1-10" or something to get the same information across, and would be less readable.

This is a profound signalling problem. The people who should be most concerned that their data could "have a widespread failure of referential integrity" are sometimes the first to have their eyes glaze over at hearing about it.

That's pretty much a TL;DR of what I was saying in the post you responded to (note the last paragraph).

"I suspect this is often a conflict between the expectations of the children of helicopter parents and my generation."

At 49, I see the exact opposite. Members of my generation tended to exhibit more tact and decorum. The urge to dress like a hobo, swear all the time, and flame everyone in sight is a classic overcompensation for years of helicopter parenting which forbade all of these things.

"In some cases, it's honesty."

In others, it's honesty used as a pretext for acting out.

In others, it's honesty used as a pretext for acting out.

Note I also make this observation.

Also note that I am specifically pointing out reactions to criticism. The other changes in decorum have been noted by previous generations since at least the 1800s. Waltzing was once a lascivious corrosive to society's morals.

Also: we are likely less than 4 years apart in age. I could do with more decorum, as I've been learning over the past 4 years.

I hear you. At the beginning of my career, I always used to be the most offensive person in the room - and I could afford to be, because nobody cared what I thought. Nowadays there are always five people in the room who are more offensive than me, but that won't stop them from complaining if the big bad ogre (me) hurts their feelings. Kids nowadays. ;)

Amost all aggressive reactions are partly contrived and controlled, even if they're occasioned by genuine emotion in the actor. You can see this from the fact that you very rarely see someone give a strongly hostile or contemptuous emotional reaction to their boss or someone else whose reaction they fear. Somehow the guys who just have strong feelings, or just have to tell it like it is, manage to tell it in a much more circumspect manner, or not at all, when letting fly would have unpleasant consequences for them rather than whoever they're going at.

Almost all aggressive reactions are partly contrived and controlled, even if they're occasioned by genuine emotion in the actor. You can see this from the fact that you very rarely see someone give a strongly hostile or contemptuous emotional reaction to their boss or someone else whose reaction they fear.

This is presuming that such fear is always the input to a conscious decision. That doesn't fit my observations of human nature. Power relationships always have some bearing on the nature of an interaction, so what you're saying is comparable to telling an aquatic species that they're wet.

Also, going by what you say, you should have more respect for those who tell truth to power, or tell their more famous/more highly regarded colleagues the plain truth. Perhaps tptacek should be more humble because he's more famous, but if it comes to the choice of him being frustrated by widespread crypto cluelessness or by a desire to dominate others, I think the former makes far more sense.

Merely upvoting isn't enough. Online bullies are cowards at heart, and it's good to be reminded of that, so thanks.

Regarding the shoes: making it clear to you that he did not mean any harm is a way of apologizing and defusing a potentially explosive situation. I hesitate to read too much into it.

Regarding tptacek, I suspect that if he had sent this to the author, or posted it as a formal review, I suspect he would have toned down the description of his reactions. I'm not sure where this review came from, but my impression is that he did not think of it as a published review that the author would see. Certainly doing such would be advisable, as people are more receptive to criticism that way.

Perhaps I am wrong regarding how tptacek would have responded had he known the review would be, essentially, published. But I know I phrase things differently in such situations.

making it clear to you that he did not mean any harm is a way of apologizing

A better way of apologizing is actually apologizing. The young man's reaction was more like exasperation that I should have been put out.

My impression is that the comment was/is a comment on social media. My comment was written in that context.

I don't know, I have problems with these things. I never know who's wrong, should the author not take it personally, or should the reviewer be tactful? I guess both.

Why hurt someone when you can avoid it?

I have a personal problem with ASN.1, and with authenticate- then- obliviously- decrypt. I don't know the author of this book at all and reject the implication that the review had a personalized tone.

Having said that: had I written the "review" as an actual "review", and not as an oversized HN comment that I had to make a Gist out of to get it onto the site, I would have written it more carefully.

I'm not saying the review was personal, it's pretty clear that you're only talking about the facts. It's just that there are phrases that have a lower "hurt-to-information" numerator with the same denominator.

I disagree: the exact turns-of-phrase that can sting also include important signalling, to other readers, of the relative importance of different points, in a way that's hard to do otherwise in prose. (In person, vocal tone and face/body language would convey these same shades of emphasis.)

As long as criticism doesn't cross the "bright lines" of ad hominem or gratuitous ridicule, as a third party reader, I much prefer the targets toughen up, rather than the critics soften their language. And there are way more third-party readers than critics or their targets.

Personally, I feel the difference is in the writing style for the medium. For instance, while a critic might remark on how 'this is such a poor recommendation that it should inspire outrage in a security-conscious developer', someone writing a comment on the Internet may use 'this makes me feel like screaming'. The language is less 'refined' and seemingly more direct though it's really saying the same (appropriate for the medium).

My hypothesis is that people expect text that has no obvious signs of being an Internet comment to use the more 'serious' language and this case (an Internet comment that is a bit longer than usual) is being classified wrongly as a result.

Yes, I think this is something that his happening here. It's at least partially my fault, because once I had to pull the review into Gist, it was easy to post it on Twitter too, and so it took on a life I hadn't anticipated for it.

I don't think you're at fault for anything. There's nothing inappropriate in your review.

It's ridiculous to simultaneously say that a piece of writing devoid of context is being classified in a certain way and to say that it contains that's inappropriate for that classification.

The mere presence of phrases like "I am not making this up" tells you that this piece is not intended to be too serious. To say that it's intended seriously but contains non-serious language is a flat-out contradiction.

It could make sense if it was published in some context, like a serious blog or a news site or something, which implied seriousness. But it's a naked text file on the internet. It doesn't have to take a serious tone.

I agree. Sometimes, the frustration also builds up if someone is witnessing a trend of nonsense, and he reads yet another thing following that trend, which triggers the writing of a rant.

That said, it's funny that most these rants aren't ad hominem, unlike some of the "formatted" vitriol which attacks you without really seeming to do so.

Someone should watch EEVBLOG on Youtube, Dave Jones does reviews and teardowns of electronics.

There was a rant over PICKit3 where he voiced his frustrations with the new device (that wasn't better than the old one, and took out nice features, replaced things that worked perfectly with things that were sort of dumb) which triggered Microchip to answer with a funny video their own.

Your tale about the boy ... Arrrghh ! I don't want to go off topic, but man, I think nothing gets diluted more than values each year.. Well, except shares of a startup once VC's get in.

Or as my 4th grade teacher used to say "Don't be sorry, be right".

Your comment actually made me read the review since it seemed really bad... but after reading it I'm just not seeing the problem.

The "I am not making this up" thing came in the context of recommending ASN.1 for instance. If that were a chess match commentary, this is where the scorekeeper would have put a "??" after the move to note the shock.

And note what tptacek's comment was not: It wasn't a bunch of personal attacks, or swearing. Some of the commentary was "more than professional", to be sure, but that's exactly the kind of commentary you should hope to get in highly-demanding, highly-selective fields.

You want to know what a perfect book review would look like in the Navy's nuclear propulsion program? It would be this: "No deficiencies noted."

I don't think either jacquesmattheij or me said this was really bad, he just said that the tone could be better and I agree. I think people are reading things into our comments.

I agree that it wasn't especially bad, it could just be worded a bit better to spare feelings.

"I am not making this up" is a succinct way to say "this was a really stupid string for the book to contain".

Tptacek could have chosen to say that differently, but it does add value as written. I have no idea what ASN.1 is; simply telling me that the book contains that string doesn't mean anything to me. Telling me that it was a stupid thing to say doesn't teach me about ASN.1 or crypto, but it does teach me about the book.

Sure, but there's a difference between "this book is really bad, it contains errors and wrong advice, I would advise against it and avoid it" and "goddamn this is literally the stupidest book that has ever been written". They convey the same amount of information, but the author's feelings are not hurt equally.

This book doesn't come within an astronomical unit of being the worst book on cryptography I've read; _Applied Cryptography_ is far worse. Which is why I didn't write anything like "goddamn this is literally the stupidest book that has ever been written".

Sorry, I have a habit of not clarifying enough. I'm not saying you said that, I'm just pointing out that one can say the same thing more innocuously if one is a bit more dry/factual.

Being totally dry/factual could mean that people don't read it and goes all TL;DR.

This condescending tone seems to be mandatory for karmic users of over 100K points :)

There must be an integer overflow somewhere.

That comment needed a ;) —it possibly comes across as much more serious and even hostile than it was meant to be.

Well tell him that's a great reaction to have in that situation. I find it mature and I wish more people would act that way.

It's unfortunate that it was too big for an HN comment, which would probably have prevented it being posted again as a topic. People who are genuinely interested in the book could have searched HN and found the original review. This thread just exists to bash/watch further bashing of the author/book.

This is an incisive criticism, but it's extremely educational in its own right. I would not have read it otherwise.

When working through basic knowledge to mastery of a topic, attempting to teach someone else is an extremely effective way to organize your thoughts and learn yourself. This is why graduate students teach undergraduate students.

The author of the original book shouldn't feel shame for making the mistake of working toward mastery of the topic. But racing to publish is dangerous when the topic is as serious as (heart surgery or) cryptography. A stern warning is worth repeating.

It's fortunate that it was posted again as a topic, as I didn't see the original comment thread and wouldn't have read this review otherwise, and I learned things from it.

Agreed. I don't often flag submissions but I'll be flagging this one.

Most of us already read the review anyway.

I have faith the next edition of the book will withstand tptacek's criticism much better.

How many books has he authored? This is very valuable data, and he stands to make an even better book even if all he does is change diffie hellman to appease tptacek and perhaps other readers.

DISCLAIMER: i know and have worked with kyle (the author).

while the factual content of tptacek's review may be spot on, his overall tone is very negative and smacks of "only experts allowed" logic. while he could have easily helped improve kyle's book and shared these comments privately, he instead chose to lambast kyle publicly, which doesn't really help anybody: tptacek looks like a total jerk and kyle now has a lot of negative attention on (this version of) his book.

this pervasive "experts only" attitude is a big part of why "secure" open source projects have hard times getting and keeping contributors. it is par for the course for people to be super rude and negative to new participants instead of trying to encourage them to improve and learn. this lack of contributors then has a whole array of negative secondary effects, like less people reading the code for the project.

The "experts only" attitude is because, well, as we've seen with HeartBleed, this is VerySeriousStuff.

If the author instead put together a book on how a layperson could perform open-heart surgery, you're damn right that actual surgeons would jump all over it.

There is some strange pervasive attitude/arrogance in tech that all it takes to be good at something is to be smart and give it a try. Why learn the theory/fundamentals when you can just start coding?

For building a web app, sure. But security is not one of those things. You actually need to learn the fundamentals and theory, and even then, need lots of experience.

That's a very weird lesson to learn from the heartbleed bug. What I learned is cryptography experts should be consulted on matters of math and ignored on matters of software. Any non-zero application of software development best practices would have prevented the heartbleed flaw, including:

1: Don't implement features you don't need. Nobody needs TLS heartbeat. Nobody. Don't implement it until you have a use case and the calling code in hand.

2: Test the features you do implement. What happens if this field is the minimum? The maximum? A power of 2? A power of 2, less 1? Negative when treated as signed?

You know what else is hard? Writing a book on cryptography. It's all very well and good to point out problems, but there are probably more productive ways to teach people than simply point out what not to do.

When you are writing about a difficult subject, you should invite reviews from experts to vet your work.

I'm not disagreeing. I'm just pointing out that a critic is much less useful than an author.

That depends entirely on what type of book is being wrote. If I write a history textbook that goes into intricate detail about the Time Slip of 1662 and the Lost Years, and the eventual Realignment that resulted in the Great London Fire, am I being more useful than a critic who points out that my history textbook is full of factual inaccuracies?

If I wrote a book on brain surgery, the critics would be much more useful than the author.

I'll take one responsible author with one harsh-but-knowledgeable critic over a hundred would-be authors without the ability to sift useful content from polemic criticism.

Well, I'll take the one responsible author now. Who are they?

I understand where you're coming from, but the author is the one who put this out in public. Publishing a book like this sends a strong message of "I am an expert, take what is written here as fact".

Maybe the tone could have been a little softer, but this should not have been done privately. The criticism of the work needs to be just as public as the work itself, so that people who might have been misled have a chance to see why.

Publishing a book like this sends a strong message of "I am an expert, take what is written here as fact".

And we, of the Internet age, should be shocked to learn this is no longer true! Eric Drexler once proposed that hypertext would save the world by allowing such peer review. Just what are we collectively missing when it comes to crypto?

It could have been couched like responsible disclosure where The Author got a 1 week grace period and worked with tptacek on getting a responsible message out.

The point of responsible disclosure is that it limits the damage done to users of the system in question by reducing the window in which the flaw is known and the systems are unpatched.

That doesn't apply for a book. Keeping the critique private for a week doesn't help the readers at all. In fact it harms them by keeping incorrect information in play and uncorrected for longer. Perhaps it softens the blow to the author's ego, but that is not at all what "responsible disclosure" is about. Helping out misinformed readers takes precedence over the author.

I agree with all your points. When I said treat this in a "responsible disclosure" method, I did really mean a grace period, for the authors sake[0]. Clearly the reasoning is not the same as a security issue, as you pointed out. I was trying to be a bit clever. My mistake.

That all said, I still think we can treat each other better. Honest question: was it necessary to destroy it in such detail? Was it necessary for the effort of attack on the "crypto box" front? It seemed personal.

[0] Contacting the author first doesn't necessarily preclude timely notice "this book is flawed" out to readers.

Yes, of the criticisms in that review, I think the "Crypto Box" one was among the most useful. He can fix that problem simply by renaming his library. The problem with calling it that is that there's also a library that provides a very carefully designed crypto_box: NaCl. NaCl was designed by someone who is simultaneously one of the world's best software security people and one of the best cryptographers. Repurposing the name like that is a little like a guy named Alan writing his own cipher and calling it "Alan's Encryption System".

What do you mean, "was it necessary to destroy it in such detail"?

If tptacek hadn't destroyed it in such detail, his review would have consisted of saying "Hey, this book is pretty bad; it's got some very serious issues, and makes some pretty terrible or misleading recommendations. My suggestion: do not read it".

Would that be better? Or would you be complaining that "Well geeze, it's not helpful to say that the book isn't good; you have to go into some detail about what the problems are so that everybody can learn!"

The idea of asking for LESS DETAIL in a criticism of a topic is bizarre. How much detail would you prefer?

While this is a valid course of action, I still feel it's up to an author to use due diligence in both researching the material, and seeking out expert advice before publishing.

Publicly discussing the flaws of a technical book actually helps a lot of people. I don't understand how it could possibly be better to have kept these comments private. By making them public, there are people who would have taken this bad advice who now know that it's bad advice. That makes us all more secure.

I really truly cannot understand the critique of an "experts only" attitude when it comes to technical books that make important recommendations for building critical systems. By all means, non-experts should experiment and build and learn. But non-experts definitely should not be giving out large quantities of advice in an authoritative tone.

> he instead chose to lambast kyle publicly, which doesn't really help anybody

It helps people who might have read the book and learned to do things the wrong way.

We can model this as "Kyle has disseminated harmful material, and tptacek is trying to contain the damage". Kyle's feelings, intentions, and hard work aren't irrelevant; but they're not what we should be focusing on.

Open source security projects have a hard time getting and keeping contributors because the expertise for this particular kind of work is difficult to develop.

Publishing a book like this sends a strong public signal of deep expertise.

I have not found tptacek to be overly rude or negative when offering advice to journeyman cryptologists. But a journeyperson should not necessarily be publicizing their how-to guides yet.

I'm sure the author is a nice guy. It is hard to put yourself out there like he has done. That said, when you put your name on something and put it in the public space, you have to be prepared for people to write these kinds of things. Furthermore, I think tptacek's blunt and at times snarky style is necessary to make his point. It is extremely hard to write clear critiques that don't sound harsh while at the same time clearly conveying the gravity of the situation. In short, tptacek can't afford the risk that softening his natural style means a major point will be missed. It's a bit like the old quote, "Sorry this letter is so long, I didn't have the time to make it short.". Politeness is a luxury one can't really afford when a book that has factual errors is already out there (and to be clear, I'm not qualified to assess whether this is true, I'm just speaking about the approach here). It is far better to write precisely what you're really thinking, than to couch it in all sorts equivocation and self-censorship.

Academic researchers get these kinds of critiques of their publications all the time. It's extremely useful to the whole academic process despite being infuriating and depressing. That said, most of those critiques happen before publication and in private. But as a book author, that's something one can control. If I were writing a book like this, my #1 worry would be that I was making claims or errors that would be held up on HN by folks like tptacek as evidence of my incompetence. I would therefore made it the highest priority to approach the most likely people to have an opinion to get them to review my draft ahead of publication. That's what people writing serious publications that have real world consequences do. Make no mistake: crypto is in this category. It's not like writing "The 4-hour Work Week", "Web Design for Programmers", or "JavaScript for Aspiring Ninjas".

If you're writing a book on a serious topic like security, you are presenting yourself as an expert and need to be able to stand up to the criticism. It goes with the territory.

It's good to stick up for people. It's less good to be thin-skinned on someone else's behalf.

Here, your attitude causes two problems.

First, you know and apparently like Kyle Isom, and so I presume you're also ready to tell me that he's an adult and a professional. Professionals do one of three things with criticism: ignore it, rebut it, or learn from it. My assumption has been that Kyle is choosing options (1) and (3) from that list. But here you are, inventing option (4): "get indignant about it". I wonder if you've thought about the extent to which people will attribute that response not to you, but to Isom.

Second, whatever you might think about the tone of my feedback, it's clear that Isom needs additional technical review for his book. Whipping up a totally unproductive us-versus-them narrative about "jerks" versus "open source" does the opposite: it generates drama. Even if you think my review was itself dramatic, piling more drama on doesn't make Isom's work more attractive to experts.

I'm not sure how big of a deal either of these issues are, but they're a bad habit for message board denizens. The exact same thing happened to Willem when he wrote his critique of the Akamai allocator, and Hacker News had a totally unproductive drama storm for a couple hours before Akamai (a) thanked Willem and (b) acknowledged that he was absolutely correct. Read the Akamai comments on the HN thread, and apply them here, substituting "Kyle Isom" for "Akamai", and I think you'll see that they apply.

Finally, I'll admit to being personally irritated by the claim that I operate from "experts only" logic with regards to cryptography. There are at last count something like twelve thousand people who have reached out to us for our free crypto challenges, and thousands of those people have gone on to solve multiple sets of challenges (something like 60 people have finished the first 6). Every damn one of those people is an email exchange that me, Sean, or Marcin had to have directly, on our own time, with no compensation --- the opposite of compensation, in fact, because we donate to charity when people finish them.

There are a lot of people on the Internet to whom you could direct the "experts only elitism" criticism regarding crypto. I am not one of them.

What's more annoying about that bogus critique is how it muddles a real issue. I'd like many more people to understand crypto and, particularly, what goes wrong when it's implemented naively. But I'd like far fewer people to plow ahead and implement their own broken stuff. The track record on amateur cryptography is bad, and what developers don't like to acknowledge is that the badness that work generates is an externality to them. People have in the real world been hurt, physically, because of broken amateur crypto. It is hard for me to take the hurt feelings of developers all that seriously by comparison.

Isom should thank tptacek for providing thousands of dollars in free consulting/editing work. He'll probably be a better engineer because of this feedback and the next edition of his book should be a lot better.

Isom doesn't owe me anything, but the notion that he might arises straightforwardly from the factionalizing that follows ginned-up outrage, which is point #2 I was trying to make above.

Ironically, you yourself are choosing more 4 than 2 in response to someone's criticism of your criticism.

I made 3 straightforward points in my comment. Do you disagree with any of them? If not, let's just agree to disagree.

I disagree with your condemnation of a behavior while exhibiting said behavior. It shows that you're okay with drama so long as it's you creating it, but you're not okay with a dramatic response to your own drama-creating.

The accusation of elitism on your part is not a new one, I don't think, to you - I found myself levying the same accusation when you decided to single out the CryptoCat project as a distinctly "bad" project, due to the number of issues that came up during the most recent security review, despite the fact that it's one of a very select group of open source projects even undergoing such reviews.

You say things like, "amateur cryptography" when it makes little to no sense. This book wasn't written for free, it was actually professional crypto, even if it had fundamental problems; it's bad crypto, not amateur crypto. When you do things like that, it comes off as elitism, whether or not you're intending it to.

I think Cryptocat illustrates and affirms the points I'm making about amateur cryptography, and doesn't rebut them.

Yes, because amateur projects generally undergo third party security reviews.

I disagree, but I'm also not interested in discussing Cryptocat on this thread, and I don't think you'd be doing Kyle Isom any favors by pushing the comparison further.

I'm just getting sick and tired of people in the crypto community dismissing projects because they're not done by one of the "ordained few".

Your criticisms of the book are indeed valid, but the obvious derision you apply when calling professional efforts such as this book and Cryptocat "amateur" is precisely the kind of behavior and attitude that keeps the state of crypto so backwards and slow, and is exactly the kind of drama you (correctly) lambasted earlier in this comment chain.

Reread the original comment to which you're effectively replying for what I think is a complete rebuttal to this comment, and, again, let me remind you that your comparison of Cryptocat and this book is unfavorable to the book's author.

I know you think it's unfavorable to compare the two, but that's the entire problem.

Your assertion that tptacek's review doesn't really help anybody is patently false. It helped me by preventing me from making the mistake of purchasing this book.

I firmly believe that you shouldn't author a book in something if you lack the appropriate expertise. If you do so, you risk disseminating misinformation at scale, causing enormous harm.

Sometimes expertise is actually required.

"this pervasive "experts only" attitude is a big part of why "secure" open source projects have hard times getting and keeping contributors. "


Not to mention the need to have to filter through all the BS criticism. I've read people arguing that there was no issue in having the e in RSA (the public exponent) equals to 1. Really.

You read that when SaltStack managed to set e=1 in their SSH replacement protocol, and what you read was SaltStack and its defenders arguing that the mistake wasn't as calamitous as it actually was. And you probably read about it because people like Coda Hale (and, yes, me) pointed it out on Twitter.

It eludes me how you turn someone's terrible custom crypto into a parable about how we should be nicer to custom crypto.

Wow...e=1? That makes me feel better about my biggest crypto goof, which I had assumed was the stupidest mistake anyone had ever made with RSA, but e=1 is worse.

Briefly, I was doing a single RSA encryption on the client and corresponding RSA decryption on the server as part of a login procedure, and using e=3 (which, at the time, was considered acceptable by most experts). Due to licensing issues the client code had to be all ours, so I was using an old arbitrary precision integer library I had written years before. It was not super fast. The multiplication wasn't too bad (Karatsuba), but division was the classical division algorithm. On the server there were no licensing issues, and I was using gmp.

So I had this "brilliant" realization. Why not do the division ON THE SERVER? The client could simply compute M^3 and send that to the server. The message would be 3 times longer but bandwidth was cheap. The server could then do the modular reduction.

I quickly made the change to the client and then started to revise the server code, when it occurred to me that since the client had made no use whatsoever of the modulus there must be a way to decrypt the message without using the modulus--like by just taking the cube root. Doh!

Yes, that actually happened:


There's an interesting real-world RSA bug related to yours: in the absence of proper padding, it's possible that e=3 RSA of a small plaintext might not wrap the modulus. A similar cube root operation produces a signature that naive implementations (the ones that check the digest embedded in a signature block, but not the padding) will validate, despite the attacker lacking the signing key. That bug bit Firefox's NSS library; for a little while, it was possible to use a short Python script to forge any certificate.

(That bug is due to Bleichenbacher, who called it a "pencil-and-paper" attack in the rump session he presented it in).

e=3 RSA isn't insecure per se, but it does magnify the impact of other vulnerabilities, and so it's best avoided.

As my literal not-making-this-up favorite HN commenter and someone who has previously expressed an interest in crypto, I'd love it if sometime you could take some time to demolish our crypto challenges. I'd be happy to send them all at once to you.

I have signed up for the first set of challenges, although I doubt I'll do well on them. I'm not very good at that kind of challenge--with crypto I tend to do better on the theory side [1] than on the practical side when it comes to dealing with breaking things.

[1] by "theory" I mean vigorous and convincing hand waving and white board diagramming...

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