Hi,
I made a new app: NFC Safe!
With NFC Safe you will be able to encrypt your private data with a NFC Tag (e.g. NFC Key Fob). You can add unlimited custom folder and entries. You will have only access to those entries with the specific NFC Tag! This is much more secure than protecting your data only with a password!
You can use any NFC Tag for this app! Your NFC Tag will be written with some data so it can only be used for this app.
NFC Safe | Windows Phone Apps+Games Store (United States)
Would be nice, if you test my app! My app is available for free!
With one of the next releases it will be also possible to encrypt/decrypt media files (images, audio, etc.)
Best Regards,
Sascha
I don't have any NFC tags on me right now nor would i really use this, but i have to say, this is a really cool idea!
While I understand if you're hesitant to post it, I'd want to review the app's source code before using it myself. Getting cryptography right, even when just using existing and well, implemented pieces, is vastly harder than getting it wrong. What algorithm do you use to encrypt the data? How about generating the key data? Are you using secure buffers? Initialization vectors? How are you detecting which key is correct for the data you're trying to access; is there a hash? What hash function? There are a lot of other important questions here, too.
With that said, the idea is fantastic. It would be especially great if you could support two-factor authentication (password + NFC tag, in this case) for extra-sensitive data, although password management in crypto has its own set of problems (what key derivation function, with what parameters? How are the password verifiers stored? Etc.)
Sorry for late reply!
xandros9 said:
I don't have any NFC tags on me right now nor would i really use this, but i have to say, this is a really cool idea!
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Then you should buy an NFC Tag! They are really cheap. For example you could buy a NFC keyfob, so you will have your NFC tag always in your pocket and as said, such a NFC Tag costs ca. 1 USD at ebay
GoodDayToDie said:
While I understand if you're hesitant to post it, I'd want to review the app's source code before using it myself. Getting cryptography right, even when just using existing and well, implemented pieces, is vastly harder than getting it wrong. What algorithm do you use to encrypt the data? How about generating the key data? Are you using secure buffers? Initialization vectors? How are you detecting which key is correct for the data you're trying to access; is there a hash? What hash function? There are a lot of other important questions here, too.
With that said, the idea is fantastic. It would be especially great if you could support two-factor authentication (password + NFC tag, in this case) for extra-sensitive data, although password management in crypto has its own set of problems (what key derivation function, with what parameters? How are the password verifiers stored? Etc.)
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Click to collapse
Hi thanks for your feedback and your questions! I think you misunderstood my app. It's not a military app, where the highest security is important! My app doesn't need to encrypt the data, because the data is stored on your Windows Phone in the application data storage. Noone has access to this. If ever any person has access to those data, you and all other Windows Phone users have a very big problem!
So, my app is an app, not a Windows Application, where virus, NSA, etc. have access to your data There are a lot of apps which protect your personal data with a password. So if someone else has your phone (stolen, or a friend while you are not watching at it), he will be able to see your data, if the know your password (this is not impossible!) or guess your password! So my app protects your data with an NFC Tag. It's very comfortable to use and faster than typing a password and also more secure, because the third-person needs your phone AND your NFC Tag.
However, my app also encrypts the whole data, so even if someone have access to the application data storage, he will be unable to read your data. Windows Phone has a built in encryption mechanism, which can be used from an API. I'm using this encryption mechanism. This mechanism uses Triple-DES. It uses the user credentials and a randomly generated password (GUID with 36 chars/numbers and "-"-sign) to encrypt the data.
Hi! Welcome to XDA-Developers, where all of your assumptions about what cannot be accessed on the phone are wrong, or will be shortly!
OK, that's half a joke. But only half... as it turns out, the claim that "... Windows Phone in the application data storage. Noone has access to this." has been untrue for months. Check the Dev&Hacking forum, especially the Interop-unlock and SamWP8 Tools threads. We have the ability to access the entire WP8 file system. Currently that access is only via MTP (USB connection), but I and other people are working on extending it to homebrew apps as well.
Moving on... 3DES (even if used with a good mode of operation and a unique initialization vector, which I am guessing you probably didn't do) is obsolete and should not be used anymore. While it is considered adequate for existing code, it should not be used in new software, and cryptographers have been recommending a move to newer ciphers (such as AES) for years. As for using a GUID as a password, GUIDs are 128 bits (the dashes don't count, because they are always the same value in the same place, and each of the other 32 digits is hexadecimal only, meaning merely 4 bits of data), which is plenty if they are generated securely; however, most GUID generators do not use cryptographically secure random number generators. GUIDs are supposed to be unique (that's what the U stands for), but are not guaranteed to be unpredictable (which is one of the key requirements for an encryption key), and the way they are generated reflects this.
Oh, and good security is important in an awful lot more places than "a military app"! In fact, there's no such thing as "military-grade" encryption, really; there's only good encryption, and encryption which shouldn't be used for any purpose. For example, modern TLS (Transport Layer Security, the replacement for SSL or Secure Sockets Layer) cipher suites are intended to be secure even against governments and megacorporations (although there is of course suspicion as to whether the NSA have broken some of those cipher suites)... but TLS isn't just used on extremely sensitive stuff like top-secret documents and such, it's also used when browsing Facebook and Twitter, or accessing Gmail, or many other things of similarly minor sensitivity.
Thank you for explaining the intended use cases of the app, though. Do please be careful when making claims such as that something is "much more secure", though; you are liable to mislead people. TrueCrypt, a PC app that performs disk encryption and is intended to stand up to very powerful adversaries, uses only a password most of the time - but I would expect that, given a well-chosen password, it is more secure than this app. There are many critical components to security, and only the weakest link in the chain matters.
For what it's worth, if you are interested, I would be happy to help secure the app (on my own time, free of charge) as it sounds like something that I would quite like to use, if I could trust its security.
What exactly is your problem?!?!
I said, that noone has access to the Application Data Storage and this is true! There is no Virus available for Windows Phone and there is no App in the Store available which has access to another app's data storage! We are not talking about some special cases where the third-person already have STOLEN your device, because nothing in this world is safe! NOTHING! Everything can be hacked! Also I didnt know that all current Lumia devices were hacked. Other devices are not relevant (Nokia has a market share of more than 90%!).
The built-in encryption mechanism in Windows Phone is the same almost ANY Windows Phone app uses! Any banking app, Facebook, eBay, PayPal. The Wallet feature of Windows Phone uses it. If you have set up accounts (E-Mail, Microsoft Account, Office365, etc.) your passwords were encrypted with the SAME API my app uses. So if you think this API is totally unsafe, WHY THE HELL are you using Windows Phone? Also Windows Vista, 7, 8 and 8.1 uses THE SAME API for a lot of thinks. So please don't use Windows anymore!
I said, my app is more secure THAN AN APP which only uses a password and that is true. Also my app additionally encrypts the data and not only block the access to the data (which a lot of other apps only do!).
Please decrypt the attached file and tell me, how you did that and how long it took Thanks!
Whoa, whoa, calm down.
First of all, don't count on that "no app in the store..." business; There's *probably* no malicious app that can do so, but OEM apps can, if they have som reason to do so, access other app's install and data folders. I've written apps (using the Samsung OEM components, which are clumsy for the purpose but *do* work) to do it myself. It's not something you're likely to see in widespread use, but it's possible.
If you aren't bothering with the case of your phone being stolen, what's the point of the encryption anyhow? I mean, prevention of data loss in the event of device theft is one of *the* key use cases for data storage encryption! It's the rationale behind things like BitLocker (which is available on WP8, but only if the user has connected their phone to a company's Exchange server that pushes a policy requiring device encryption).
If you were honestly worried about market share, you probably wouldn't target WP at all; Nokia's fraction of the WP market share is lower than WP's fraction of the smartphone market share. Nonetheless, you are correct that, at this time, Nokia WP8 devices haven't been cracked. Nor have HTC's phones. I'm confident that this will change in time, though. You might have misunderstood my little joke at the start of my last post... but breaking into smartphone operating systems, getting past the lockdown policies that say "noone[sic] has access" (it's "nobody" or "no one", by the way) and taking those decisions into our own hands.
I guarantee you that the vast majority of WP apps don't use 3DES. I *know* full well that the Microsoft code doesn't; they had already deprecated that cipher years ago, when I interned there, long before even WP7 existed; its use was prohibited for new code. Just because you used the DPAPI (Data Protection API) doesn't mean you used it correctly (and by the way, that internship involved working on encryption in Windows, writing test tools for it). Please don't take this as some kind of personal insult; in my line of work (security engineer), I see a ton of misuse of cryptography. It is, as I said in my first post, hard to get right. That's why I offered to help.
I'm not going to bother taking the time to figure out what cipher you used on that file, and what its contents are supposed to look like enough to start doing any cryptanalysis, but I guarantee you it's not very good. There are repeated patterns, including long strings of null bytes, that are phenomenally unlikely to occur in a file that short after passing it through even a half-decent cipher (we're talking 1-in-several-billion chance here, no joke). Coming to this conclusion took all of a few seconds, by the way, using no tool more sophisticated than Notepad++. If I was pulling it off of a phone, I'd have a lot more idea of what type of plaintext to expect, and I could examine the decompilation of the app to see what ciphers were used, which would make things a lot easier. I'd say "for all I know, you just took the output of CryptGenRandom and put it in a file" but if you had, it wouldn't have had obvious patterns in it... in any case, it doesn't matter. I don't have to prove anything to you. I'm *trying* to help, and offer some good advice as well, but I can't force you to take it. There's no call for getting defensive, though. I wrote a file encryption utility myself one, in fact. It sucked, so then I wrote a program to break its encryption. Both experiences (but mostly the latter) taught me things.
A new version is available now, which includes image/photo encryption, OneDrive backup, bugfixes and other small improvments!
http://www.windowsphone.com/s?appid=0a8656d4-ed32-4bb5-baac-1317827e18d8
Hi,
I have a question:
My app is available in German and English since one year now! It was downloaded over 1000 times in Germany, but only 80 times in USA, UK, etc. I got 40 reviews (4-5 stars) in Germany and only one bad review in USA. So could someone explain what's wrong with my app? Is it not visible in the US Windows Phone store? Is my app very bad translated? Are there no Windows Phone users in the USA? Or maybe no one use NFC in the USA?
Best regards,
Sascha
Sorry, I don't tried your app yet but will try to answer your questions.
First, probably it's something wrong with your marketing, not the app Le me say: 1080 downloads per year - it's too small number (even 1000 in Germany). For example, my "marketplace entry ticket", "Lunar Lander Touch" app, very unpopular and underrated (but it's still one of my favorite games on WP, and good alcohol tester ), has 4078 for the year 2013.
As for NFC: I've tried to use it but stopped because of very uncomfortable WP implementation. That service should work flawlessly, without user interaction, stupid questions and dialogs, to be useful and popular. But unfortunately it's not (for the Windows Phones). Microsoft must add an option to disable NFC warnings.
P.S. I may recommend you to use "Snowden case" for advertizing
Thanks for your feedback!
Yes, I know that the download numbers are very bad, but I don't have an idea how to improve this. Because of my app is free and my private hobby I don't have money to buy ads, etc.
Improving my app had not effect. Thanks to DVLUP I "bought" ads for 50$ with AdDuplex, but this also had no effect.
It's really hard for individuals to get their apps famous and in a higher ranking in the Windows Phone Store without investing money
I understand... AdDuplex is really bad: I've tried once ($100 from DVLUP meeting plus I've bought another $100 coupon for $40) during a week - no results at all. Complained to AdDuplex support and manager gave me additional $300 for free, to spend within one day (sic! He-he, I wish to get $300 daily from my app!) - still no visible results, just a regular download fluctuations...
What you may try: advertise on more forums, prepare good pictures/screenshots; may be, video clip "howto" will be helpful. Embed RateMyApp Nokia's control (check NuGet) to your form. If you have XP on DVLUP, spend 'em for advertising campaign (these ones are extremely effective!).
P.S. I also thought about xda-based developers club, with "rate 5 stars my apps, and I'll rate yours" rule but I don't know how to implement it properly (but good customer rating is very important for the app distribution).
Thanks!
I already added RateMyApp. This was really helpfull to get more reviews. It's a pity that I had not implemented such a thing from the very first time my app was added to the Windows Phone Store :-/
I "bought" 1 week in App Social (DVLUP). Hope this helps. But it is also only in Germany.... I have enough users and reviews in Germany, I need them in USA, UK, etc. The problem with the DVLUP campaigns is, that you need at least 50 or 100 reviews (and 4,5 stars) as a requirement for the advertising. But you don't have so many reviews and that's the reason why you need the campaign to get more reviews, but you can't buy the campaign... A vicious circle!
I will do my best to get more downloads in other countries than Germany!
Hey, thanks for this app i find it realy useful.
Danke!
And here is the idea for the ad banner
Great idea
btw: Version 2.1 with new type "User Credentials" is available now!
Ok, I stopped developing, it's not worth. Sorry!
Hi all,
I'd like to share great news. Sicher, our free secure messenger finally comes to Windows Phone.
Sicher features true end-to-end encryption of both text messages and file attachments. With anonymous push notifications and the ability to set a timer for when messages will self-destruct, Sicher also includes password protection for the app itself.
Please try Sicher and share your feedback in this post.
FairyMary
Sicher Team
App is free, store link is here: EDIT: Removed because this thing looks like a scam and its description is a lie
I haven't been able to find a lot of info about how the app works (I'm talking about at a very technical level). My general advice regarding crypto code is to open it up for review, either publicly or by a professional security assessment firm (disclaimer: I work at one of those). If the code is already open for review somewhere, that would be awesome; if not, I recommend getting in touch with some external security experts (same disclaimer, but I can provide contact info if you want). The Internet is full of things that the developer claimed (and often even sincerely believed) were secure.
Aaaand just for fun, I decided to take a look at the app and see if there was anything obviously wrong. Let's start with the presence of no fewer than *three* advertisement networks, shall we? Begun Advertising is Russian and Google-owned, Google AdMob is self-explanatory, as is Microsoft Advertising Mobile. Your store description claims you
don’t use any advertising engines
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. Did you really think nobody would check this?
WTF are you trying to pull here?!? I can't think of any way to faster burn trust in a "secure" app than to make a claim that is trivially disprovable in a way that benefits nobody except you.
I'll come right out and say it: Sicher looks like a scam!
Oh look, a Facebook library as well. Totally expected to see that, given that you
don’t integrate social network SDKs
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Click to collapse
Oh, and before anybody asks about responsible disclosure, that's for when there's an unintentional bug in somebody's code. This just looks like pure exploitation of your users! (I say "looks like" because I haven't actually decompiled the code to see if those libraries are being used, but it's hard to imagine why you'd have them otherwise...). The only responsible way to disclose malware is to do it publicly, and this looks malicious.
EDIT: I'll give you 24 hours to give me a good argument why I shouldn't report my findings to the stores themselves.
Time's up. You actually got over 48 hours because I was busy yesterday. Hope not too many people got scammed and tracked by your "secure" and "private" app...
Hey @GoodDayToDie, unfortunately I don't know where else to ask this, since you seem to be really interested (and skilled) in this topic, what messengers do you consider secure? WhatsApp is obvious, the only ones on Windows Phone I know of that come to my mind are Telegram and (soon) Threema.
What do you think about the two? I have basically no knowledge, but what seems odd to me about Threema is their faqs answer to "what about MITM?" they just say they use certs, hardcoded in the app. Aren't they with their servers in control then? How I understand this, the Threema servers could perfectly perform a MITM attack.
And Telegram has a completely confusing protocol.. So please share your thoughts!
I have no personal knowledge of one, sadly. Take anything I say here with a huge grain of salt (including the fact that Sicher looks like a scam; I haven't actually verified that it *uses* all those ad networks + Facebook that it integrates, just that it has them) as I'm not spending the time & effort for a full security review of these apps at this time.
Threema actually looks quite good.
Pros:
They don't try to implement the crypto themselves (they use NaCl, which is both written by people who know what they're doing, and well-reviewed).
The design of their end-to-end solution makes sense (it connects through the server since phone networks won't allow incoming/direct connections, but the messages are encrypted to only the recipient and doesn't require that the recipient be online to receive the message).
They are relatively open about how things work (although those *could* be lies; I haven't pulled the app apart).
It is possible for the user to verify the key of another user.
Cons:
They don't have Perfect Forward Secrecy on messages. PFS would require that the intended recipient be online at the start of any given conversation (to negotiate the ephemeral keys) so this isn't terribly surprising, but it is disappointing. An attacker (including a government agency) who gets access to your private key could decrypt historical traffic to you if they'd recorded it.
The app is proprietary; there's nothing stopping them from pushing a malicious update.
The server supplies the public keys of users; until such time as the user validates the other party's key (which is difficult to do except in person) the server could have sent a public key that the server has the private key for (instead of the user's own public key) and then MitM the user's traffic. This would break down when verified though, unless the app lied about the result of the verification process (you don't actually see the key itself).
To address your concern about MitM, the app says they use certificate pinning (a standard and very smart security measure, assuming they did it right) for app-to-server communication, so nobody (including third-party security engineers) can MitM the app traffic. They also claim to use PFS. However, if the server itself is untrusted (i.e. some government thugs show up to demand access, although bear in mind that apparently the servers are all in Switzerland) then the server could give you the wrong public key for a user you try and add, allowing the server to MitM you. Also, the company could push an update that is malicious.
The only protection against the server-sends-wrong-key threat is to either require that the user manually import all keys (think PGP minus keyservers and assuming trustworthy key exchanges) or exactly verify the key (i.e. personally ensure that it matches the other user's key by actually checking the bytes or at least the hash). The only protection against the malicious update is to make the source code available and have a method by which users can either compile it themselves (though see "Reflections on Trusting Trust") and/or have a way to verify the application binaries.
I'll look at Telegram later. For the moment, though, I would loosely recommend Threema once it's available. There's also Skype, of course, but while it was decompiled once long ago (and found to use secure encryption, although some non-crypto vulns were found) that was many versions ago (and, in particular, was before Microsoft bought them).
Hello.
I am here seeking for help and advice on how to approach the development of a security framework (via APP or via hacked Android ROM to be used by kids, that could be monitored by adults (parents or legal tutors).
The idea would be to develop a (white hat) hacked ROM, that would allow the kids to communicate with their friends, but also would allow their parents to supervise/monitor in real time what their children are doing, who are they communicating with and that way protect their children. The thing is not to spy on our kids, but to be able to check regularly if there is anything wrong going on with our kids (mobbing, insults or harassment). Kids aged (10-14) could be influenced by other kids, adults, or adults simulating being kids, and on some occasions they can be tricked to do things without their parents consent/knowledge that can lead to a tricky situation.
When I was a kid, we had the telephone (wired telephone, of course) on the middle of the hallway, so all our conversations were basically family-public. The truth is that there are not many secret things a 10yo kid could/should talk about, but nowadays, it could be a little bit worrying to lend a smartphone to a kid. I think it's just as letting a kid drive a car; he can do it right, or not be able to evaluate the whole consequences of driving a car.
Talking to other parents around me, they all found very interesting the idea of having a telephone that one could lend to their son, having the kid available all the time, and with the peace of mind that you could know what's going on. Of course the kid should be aware of this, and that the telephone comms are being supervised. I think it's no big deal. "Kid, it's very simple. The telephone is mine, and if you want to use it you have to use it under my terms".
Probably, all of us working for a company, have also our communications supervised, cannot make personal phonecalls with the company's telephones, probably cannot navigate to webs looking for personal content, and we asume those rules (because neither the company's phones nor the computers are ours but our company's). It's basically the same, switching the company-employee role to a father-son one.
So, let's get to the point (technically). I am a tech-geek, linux pro-user, have compiled a few ROMs just for personal use, but don't feel capable enough of starting a project of these magnitude alone. If there is anyone willing to help, opine, or whatever, will be very welcome.
First of all, APP or ROM? I basically think that the ROM is the way to go, but I'm asking just in case someone can convince me on the contrary. I will make a poll on this question.
APP An APP could be easily downloaded and installed but would require a rooted phone, and I don't see it clearly if an APP could resolve all the needed issues (access to communications for example) and could be fairly easily uninstalled too.
ROM On the other hand, a ROM would be trickier to uninstall (basically flashing another ROM) but wouldn't be as easy to install as an APP (though the installer model of cyanogenmod could be kind of a solution). There could be an universal (if possible) independent flashable module, over whatever android ROM, or an entire ROM solution.
Features that I want to develop in this ROM (by the way, I call it 'Vigilante ROM'):
Suitable for as many devices as possible
Web interface for parents available to see device-related information
Some hack-proof measures to avoid kids bypassing the ROM's security
Alerts triggered on some events (offensive words, whatever)
Position of the mobile -just in case-
Suitable for as many devices as possible
The first thing I though was what platform should be used for this ROM. To select Android over others (iOS, Blackberry, W7) was a no-brainer. Now, the question is should we use pure Android or make a CyanogenMod fork?
In my opinion, even though every phone maker has to supply their ROM sources publicly, they usually introduce so many modifications (HTC Sense, Samsung Touchwizz and so on) that it looks more difficult to develop a common security framework over each manufacturer's version of Android, rather than using a more standardized one like CyanogenMod.
CyanogenMod already works with a wide number of devices (and a wider one if you count the unofficial supported devices), I think CyanogenMod should be the base of this ROM. If all the 'things' needed could be flash on top of any Android device, would be even better, but technically I need help with this one.
I understand that basically there should be an internal proxy setup, so that all the communications go through this internal proxy, and based on the kind of communication, we could log whatever we need. For example:
Visited URLs
Whatsapp or other messaging apps should be decrypted
Incoming/Outgoing calls/SMS
Social network activity
I know the Whatsapp protocol because I'm familiar with a project called WhatAPI. The key point to be able to intercept whatsapp messaging is a key generated and exchanged during the app install (although there are ways to later ask the Whatsapp server to renegotiate this keyword) and that's used later to encrypt all the messages between the phone and the whatsapp server.
Web interface for parents available to see device-related information
Behind every kid with a smartphone there should be a responsible adult supervising the kid -even if it's remotely-. In my idea, logs of messaging activity, incoming/outgoing calls/SMS and even the position should be available to the supervisor through a web interface.
Some hack-proof measures to avoid kids bypassing the ROM's security
That's an easy one. CRC checks on some keyfiles would guarantee that the device is not being 'counter-hacked'. Some kids are also very techie, and we should make some defences against kids trying to hack (counter-hack?) the phone.
Alerts triggered on some events (offensive words, whatever)
It could be interesting if somehow the supervisor could receive a notification whenever the kid sends/receives and offensive word, or tries to enter some special tagged website.