How much reliable encryption algorithm? Can I change it?

How much reliable encryption algorithm?
AES-128 algorithm is a symmetric block cipher adopted as an encryption standard by the United States Government according to the results of the competition (see. Wikipedia, google).
even as far as I know nobody has been able to crack it.
Can I change it?
No you can not because:
1. Implement a bunch of a cryptographic algorithm, encryption I'm not interested
2. AES-128 is very reliable. If AES is hacked, then realizing more reliable :)
The aim of this project to write a SMS Messenger which has an extremely easy interface and allows you to send messages that reliable encryption algorithm.
In this direction, I plan to develop the project.

Thanks for the answer. It must be installed at the sender and the subscriber, and the key is provided?

Checked, nice and simple, but the two words are transformed into 3 rows of text.

Post has been editedvadeus - 08.12.14, 11:09

It must be installed at the sender and the subscriber, and the key is provided?
1. Yes, the program must be installed at the sender and the subscriber.
2. The key is not provided. The key specifies the sender, otherwise the program does not make sense.
Checked, nice and simple, but the two words are transformed into 3 rows of text
In the description of the program there is a point:
- encrypted text may be longer than the original. The number of outgoing messages is displayed in the lower right corner of the screen
Those. do not look at the amount of text and number of messages that will turn the text. Those. a figure in the lower corner of the screen multiplied by the cost of 1 SMS will cost an encrypted SMS.

A bit of theory
If you use 7-bit encoding (the Latin alphabet and numbers) can send messages up to 160 characters.
SMS written in Cyrillic, can not exceed 70 characters.
Regardless of the language in which it is written SMS, the result of this encryption program is in Latin, because the ciphertext is limited by the following symbols: the numbers 0 to 9 and the letters A, B, C, D, E, F.
Those. long text does not always mean expensive: rolleyes:

Thank you for "just" and "beautiful" - this is my goal

In short, I understand the problematic application.

and on the basis of what you have done such a conclusion?
Functionality stated in the description does not match reality? We found a mistake?
The application does not meet expectations? What's wrong?

the new version 0.96. A little modified interface.


ProtectedSMS.apk(667.38 KB)

new version 0.98


ProtectedSMS.apk(1.79 MB)

New version 2.1
Added option to exclude unknown number from the list


ProtectedSMS.apk(1.8 MB)


Post has been editedp_al - 18.12.14, 16:19

New version 2.3


ProtectedSMS.apk(1.8 MB)

Very desired application. But organized very uncomfortable. speremeshku all displayed messages. Developer organize your messages in alphabetical order, as in the standard otsylalschike !!!. Of the benefits of the opportunity to set a password, IT IS REALLY COOL !. At any instant messengers lauded it is not clear who is in addition to the sender can read. And this all specifically - who said he read the password. Who does not know him (cops, enemies, dyuzhe curious) not read!

Thanks for the tip, the next release will add a list of the sort.

The application does not set but from the description I realized that I can say to take to send a "hello" through this program recipient receives the encrypted text to read it he needs this program and code.
Assume a situation where someone is sitting at the (enemies cops, etc.) I've got something to tell him that I told him I write 'hello' and I still have to tell him the code. Let's say I send him a text. What prevents the enemy to read? I mean am that some goals at the program? any developer working options is why we need his program?

For me, the purpose of writing an application to get rid of nasty feeling that the message can be easily read by anyone.
The process of sending / receiving SMS:
1. write the text and press send
2. preservation of SMS in the base phone 1
3. sending SMS operator
4. preservation of SMS server of the operator, the operator itself without your consent
5. send to the recipient operator text messages
6. The notice of receipt of SMS and SMS saved in phone-based 2
7. The text is received and can be read
Thus, all posts could be kept in the public domain as a cellular network (step 4). This program encrypts text messages before step 2 so the text message is protected immediately at all levels of the messaging process. The circle of people with whom I associate with this application know the password in advance. My personal opinion on the built-in key, it is very unreliable especially when the same key for all users, but you do it can be more.

As I understand it, in the theme developer is present. The program is without any doubt very useful, but still green. I put, like works fine, but for some reason I can not remove the person from the program. It is not good that the program has access to the Internet. I understand that for broadcast advertising, and after the purchase of a banner ad will disappear, but access still remains. It may be better to make a trial version, and the ful version of the paid and do not have internet access. Of course it is possible and to block this access, but not all have Ruth.
I hope that the program will continue to evolve. I wish you success!

Thank you for your attention to this project!
Yes, I agree the program is still green, but at this stage the goal to implement and debug the basic functionality. If on deleting messages, this is a known limitation that is present in the program description. The problem with removing / changing the SMS originated due to the restriction imposed with Android 4.4. Change the SMS database can only program which is the default program for receiving / sending SMS:
http: //android-develop...-ready-for-kitkat.html
Thus the need to have a full messenger to implement this functionality. And as to write a complete and well-functioning messenger just not real to me, I decided to move towards this goal gradually.
On the division of the project for the 2nd program, I agree, but at this stage I will not do that because it seriously slow down the development of the project, as the need to work with two versions of the code. Maybe in the future, but not in the near.

Thanks for the answer. With great interest, I will follow in the future will develop the program. You enter the price in the store. The fact that the purchase in the program has been written, and no skolko. I price 1,20 €.

My price is $ 0.99 and google does not make it less as she grew up to 1,20 € a mystery to me, probably the price varies from region to region, and taxes paid by google. Because you price € 1.20, which is clearly more than $ 0.99, then it tough to score in the description will not work. The console interface google I have not found how to make a bid for the purchase of the visible, and according to the following article: purchase price must be displayed without me if this was done Google:
http: //www.androidpoli...tore-later-this-month/

No mystery no. Simply, we were in the euro area, and google has changed the price of LTL in €. So much so I changed that prices have risen significantly. When prices were LTL they comply with the dollar, well, and now the horror! Oh how annoying this ezona.