Sure, if you throw away the salt. But what's the use case, couldn't you just generate random bytes instead?

The use case is destroying actual data but retaining some uniqueness / consistency constraints.

With the added caveat that md5 is more convenient than other alternatives.

After throwing away the salt you are left with nothing but random bytes (assuming the salt was random), what's your plan to reproduce / check consistency?

Edit: Oh, wait. I guess you are planning to re-use the salt for the entire process and then throw it away? Technically not secure in that case, it might be possible to re-construct the salt given enough of the source data + results. Use a secure hash if it's sensitive info.

yeah 32 bytes = 2^256 different salts. even though you can attack md5 at an insanely large number of tries per second, it's not large enough to overcome that size.

EDIT: unless there is some other, non brute force technique i'm not aware of....

Meh, looks like the best preimage attack on MD5 is actually 2^123'ish from 2009.

In your case there are are large number of hashes + some parts of the pre-image(?) known, which i guess could make things worse in theory. But you are probably fine in practice.

Any reason iOS programming specifically?

- It's a declining market. The days where you can make a cool app and make money are gone.

- It's not a good choice for beginners because a lot of what you have to learn is specifics of the API rather than fundamentals of programming.

- The skills are not transferable. Swift and Obj-C are not used for anything except iOS programming.

Plenty of high paying jobs though.

ChrisV makes a lot of good points.

If I were starting out today I'd learn how to develop responsive html5 apps. Javascript is everywhere and only getting stronger.

Or if you want something more traditional, you can't go wrong with Java. Java is the Cobol of the future.

Which reminds me. If you don't mind old tech and want 100% job security, learn Cobol. It still has the most lines of code running in the world (I think) and the generation of people that know how to maintain cobol is dying while demand for workers isn't.

Can't speak to that, not living in the US. I feel like that is unlikely to continue to be the case in the longer term though.

As long as doctors are pretentious *******s, there's job security

I'm finally ready to do it. I want to nuke Windows and install Fedora on the metal. What problems are likely to happen if I do this? If it goes really bad, I'm totally screwed.

define 'really bad'

You won't be able to play games or use a decent office suite without jumping through hoops, that's about the worst that can happen.

I realized this is the flaw. If you have a small number of possible values that an attacker knows about or can guess (for example if you're hashing things like an empty string or a persons first name) then they can probably figure out the salt. And once they have the salt they can figure out the rest.

Edit: still think I'm fine though. And I can actually make the salt even bigger without any problem.

For iOS, and I'm not sure about others, there is a lot of demand for good iOS developers. You can't just go through a boot camp and expect to find a good paying job like you do with web dev.

It's a declining market if you are trying to be a solo dev making apps. You won't strike it rich there. However I think the demand for companies to have their own app is growing. And it is often some kind of CRUD app communicating with a server.

I'd argue that companies wanting their own app is a declining market. There seems to be a pretty big backlash against sites that do the whole "Download our app!" Thing whenever you visit their site.

Phone hardware getting stronger and front end tools getting better is making it easier and easier to build a web interface instead.

I hope you are wrong. I hate web dev with a passion. I don't know why. I don't see myself ever doing it. Maybe CS has no place for me.

Can you afford a hard drive? Take the hard drive out of your system, put in a new one with no OS, put your new OS .iso image on a memory stick and boot off the memory stick. In that way you save your Windows hard drive. And while you are at it do yourself a favor and buy an SSD as your new hard drive.

You will be fine, I think web dev will continue to evolve too. I think blacksize5 is right FWIW in identifying the trend. There does seem to be a high level of demand for iOS developers too.

Agreed that the job prospects are solid regardless of the way things are trending.

I'm curious why you feel that way about web dev barrin. There's not much difference in building crud apps on iOS, Android, or a server.

This implies not only that there is no difference between Android and iOS programming, but also that there is no difference between client side an server side programming. The former is not true, and the latter is very not true.

When I lived in SF, a friend of mine said in an angsty moment of reflection, "Man, it just struck me, our whole job is just pushing data from one place to another..."

Which is true, in exactly the same way it's true that writing is just pushing letters around on a page.

I didn't mean that there are no differences, just that the design patterns are similar making it pretty easy to transition between the three.

What I was getting at is that in my experience they don't feel different enough for someone to have such a strong preference for one while totally rejecting the other

I could totally be wrong, but the way I look at web-dev, it's all about making things look nice and pretty. Making sure you got the right layout, css, colors. Making sure it works with 10 different browsers. Don't get me wrong, we have that in iOS, though I feel that with the tools we have, it's such a small part of our development process. In iOS we have bigger things to worry about, eg. managing resources on a memory/battery constrained app.

In my app that I just released, I spent 90% of the time designing the logic of how objects are updated and moved around. The 10% was on the design, which I hated.

I like optimizing things, making things go fast and be robust. Getting stuff to scale. Perhaps backend development is for me? Not sure if that's the correct path I am looking at.

i think you're right that a good dev in one could become good in another in 3-6 months, because the foundational skills are the same.

but, eg, a big part of an android developer's job is cross-device coding and testing, because there are so many device types, screen sizes, and versions to support. it's arguably even worse than web dev requiring old browser support. so just that might be enough for someone to hate android dev but enjoy ios dev, for example, even though they're "more or less the same." and then there are personal and political idiosyncrasies -- some android devs hate what apple and its closed ecosystem stands for, or simply dislike apple's image. and i talk to some young developers who have no interest in backend work just because "mobile" seems cooler -- their friends all have phones and "making apps" has more cachet.

which is all to say that details matter. i understand where you're coming from but i think it's too large-grained a POV to be useful in understanding behavior and preferences.

what you hate is front end design work. especially in a complex SPA app, you might have developers who never even touch design, even though they're working 100% in javascript. you have design, client side architecture, and backend architecture, just like you do with iOS. and from what i've seen of our iOS dev (who does the design and architecture) hacking away on layouts and pixels is not much easier than it is with CSS.