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Questions tagged [encryption]

Process of encoding information such that decoding requires the knowledge of some secret (a key). This tag covers questions about obfuscated and encrypted programs, or tools, but higher level questions may get better answers on [crypto.stackexchange.com](https://crypto.stackexchange.com/).

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2answers
209 views

XOR encryption - How to find the key?

I'm trying to solve a crackme which basically uses a XOR encryption scheme in which the password is used as the key to an encrypted buffer which is subsequently executed. The following is the ...
1
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0answers
95 views

Reverse crypto algorythm, based on AES

Hello! I'm working on reversing one library (shared object) written for ARM architecture. It's obfuscated or packed with something pretty strong what makes debugging much harder and almost impossible ...
1
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1answer
86 views

Reversing a Java digest function, with known public key and source code

A Java application verifies that an XML string that came from a clearnet server (no SSL) has not been tampered, using a message digest. It does so with a public key stored locally, accessed with the ...
0
votes
1answer
74 views

how to find private Key and passphrase stored inside a program?

There are some files (drivers) that are encrypted, and these files are working in a program that is installed in my computer. The program using these files needs to decrypt them. I am sure that the ...
0
votes
1answer
87 views

Algorithm to find secret cipher S-box in bin file [closed]

Is there any algorithm that searches through binary file and detects existence of secret S-box built from look-up table (4 bit or 8 bit)? Consider the sbox is unavailable for public The attached bin ...
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votes
1answer
191 views

How do i find the decryption key for a encrypted text file [closed]

So context i have a game and a encrypted save file. My thoughts were how to find the decryption key in reverse engineering my game .I watched tuts but i think this topic isnt much detailed so i need ...
2
votes
0answers
77 views

How should I got about working out the format for this psp game?

I have been attempting to reverse engineer a format for a visual novel psp game ('Mirai Nikki RE: WRITE - 13 Ninme No Nikki Shoyuusha') and I have come to the understanding that the format works as a ...
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votes
1answer
51 views

How to use Python while debugging in IDA

I'm debugging an .exe file in IDA. At a specific point during debugging, I want the Python code to automatically take the data in *(eax+8) and encrypt it with that module and print the result to file ...
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votes
1answer
334 views

How to install ida plugin to identify encryption function

I saw here How to identify known encryption algorithm? the IDA plugin https://github.com/nihilus/IDA_Signsrch I don't understand how to install it . In the INSTALL I saw coppy the plug-in and ...
2
votes
1answer
429 views

How to identify known encryption algorithm?

I reverse an .exe file with IDA. I see a function that appears to be encrypting something by generating some random numbers. It there any tool to identify if it is a known encryption algorithm?
2
votes
1answer
120 views

How can I generate the recovery password on a legacy system (Original company is out of business) running on my local machine?

I'm attempting to use a legacy systems recovery feature that typically required calling/faxing a company that is no longer around. Basically, the system was designed to go into a recovery mode and ...
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1answer
269 views

Identification of AES portion code in binary

I want to locate AES code portion in binary after reverse engineering. I have tried to locate manually and using plugin findcrypt2 but I was not successful. Kindly show me a direction so that I can ...
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vote
1answer
1k views

Decrypting SQLite Database with key

I have a SQLite database that contains a dictionary (just words and definitions) that can be opened with free but proprietary software. To use with the software, it requires an 'unlock' key, which I ...
0
votes
1answer
99 views

Does someone recognize this “lookup table”? (used for xor encryption)

This table is part of the packet encryption of an old game for which I am developing a server. The crypto algorithm doesn't just xor the password with the message. It uses a multiple of the ascii ...
1
vote
1answer
296 views

Binary encryption

I'd like to ask your help to understand the algorithm used to encrypt these hex/bin firmware (for an ARM-Cortex M4 microcontroller). In the tar file above you can find different firmware versions. ...
2
votes
0answers
571 views

Arm hex firmware reverse

it has been a couple of months that I'm working on the firmware produced by a company that makes (not licensed) gamepad console adapters. One of my goal was to understand how they bypassed (hacked) ...
0
votes
1answer
149 views

Encrypted String? [closed]

(I made a topic but I was ask'd to re-made it) Hi! I have a program and when I want to decompile/dissamble it finish and when I inspect the code everywhere where should be some filenames there are .(...
3
votes
1answer
2k views

Finding the encryption key in a binary - IDA Pro and how an S-box might be represented in the binary

In practicing reading source code and analysing I've been looking at a program called aescrypt2_huawei which floats around the web and encrypts/decrypts the XML config file from Huawei routers like ...
1
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0answers
255 views

Need Help decrypting .luac files

I have been recently trying to decrypt .luac files inside an encrypted android app. I tried to follow some of the previous threads here but the following frida script didn't give any output. ...
2
votes
1answer
172 views

reverse checksum algorithm

I'm working on this pseudocode trying to find the correct input for the expected calculated value (i'm not sure if i can call it a checksum). I can't focus enough to generate the reverse algorithm, ...
1
vote
1answer
160 views

Unable to find Send/Recv type calls in Network Application

Target is protected by nProtect Gameguard. Packets are encrypted. Goal is to obtain unencrypted packet information via the client. I obtained the free, 5.0 version, of IDA, and disassembled GVOnline....
2
votes
1answer
3k views

How do Enigma, Themida and VMProtect compare to each other?

I'll be releasing a piece of software soon and I'm looking for good protectors. The three that came to my attention were: Enigma, Themida and VMProtect. I searched a lot online but I couldn't find ...
4
votes
1answer
876 views

TP-Link encrypted backup file TX-VG1530

I have been trying to wrap my head round this stuff so bear with me. I have a Tp-Link TX-VG1530. From the gui you can download the config file however the file is encrypted, I include a portion of ...
1
vote
0answers
528 views

How to decrypt .jpg files of comics app in a C Program?

I'm trying to decrypt jpg images of comics I purchased in my comic reader app on android but neither I can view them (after copying from SD card to Windows desktop) nor can I convert them to pdf to ...
2
votes
2answers
262 views

Emulation Project - GameGuard Protected Client

I'm not new to MMO Server Emulation, but I am new to working with a protected Client, and have very basic RCE skills. I would appreciate some direction, and maybe this won't be possible, given the ...
0
votes
1answer
232 views

How does a Smartcard work? [duplicate]

It appears there is more than just flash memory on Smartcards. Presumably there is also some sort of microprocessor. So then along comes this article: Crippling crypto weakness opens millions ...
4
votes
0answers
470 views

Obtaining the decryption keys for Super Mario Run (Android/iOS Game)

Super Mario Run is a il2cpp Unity game. Most of its assets are downloaded in-game through http requests. I particularly want the OGG files of the music. I can see the list of their names comes from ...
4
votes
2answers
737 views

Identify password generation algorithm

I'm a newbie who just started own way through reverse engineering so I apologize if my question is not appropriate. Currently I'm going through different Crackme puzzles and now I'm stuck. I've spend ...
0
votes
1answer
129 views

Checksum in CAN message

I'm trying to fake a CAN message, but I'm not able to understand how the 8-bit checksum is calculated. The checksum follows a pattern along with a 4-bit rolling counter. As long as the data of the ...
0
votes
0answers
72 views

Decoding this value & What encryption is it?

I've got this value, which I think it may contain date, that I want to decode ( decrypt ) and to know what encryption type is it. 3zsWFYXd1Eg= At first, I thought it's a base64 encoded string, But ...
2
votes
1answer
379 views

Help me understand how to actually break an XOR/Vigenère cipher

My friend's server was recently hacked and I'm trying to decipher the malicious files I found in hopes of understanding the hack better. I can tell that they're using an XOR/Vigenère cipher and I've ...
2
votes
2answers
168 views

How can I identify how this string is being encoded so I can replicate it?

A friends company uses an old VB6 application to generate encoded strings to then use in their also old and out of date database system. They have the application running in standalone mode so I can ...
1
vote
1answer
312 views

Defeat RSA hash verification - QNX working example

I really liked the answer in this post: Defeat rsa hash verification However I do not really understand this part: "taking the signature s raised to the power of 3 modulus n we wind up with the ...
1
vote
1answer
118 views

What does this sequence of numbers mean?

so i'm reversing a file format of game. As far as i can understand the file i'm trying to reverse contains compressed textures. I'm already able to locate the textures and decompress them, but i'm not ...
1
vote
1answer
120 views

Do TPMs Send Stored Keys in Plaintext?

As you may know, the TPM (Trusted Platform Module), which resides on the LPC bus, allows the storage and retrieval of encryption keys and certificates securely. Within this Trusted Computing concept, ...
0
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1answer
1k views

.dat file how to Encryption and decryption?

I am trying to decrypt or unpack a .dat file I used a variety of methods, but do not work When opened in notepad the text would look like these: luRd+WbiiNGDNgs3XLX1fA== vtAQlLx3N6HybkYYif3pAg== ...
2
votes
2answers
1k views

How to get file back from generated sha256 checksum?

The title seems little crazy, but I think that it is possible. Just think about it. If you create text file like this: Hello world! You get this checksum: ...
0
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2answers
735 views

How XOR works in my code?

I have this assembly code: XOR DWORD PTR DS:[ECX+EAX],1234567 And what it does is just xoring the first 4 bytes of EAX with 1234567. So if the first 4 bytes are : 31 32 31 32 After xor they become:...
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votes
1answer
214 views

Is there a way to find out which hash standard by studying the source code?

We have an embedded product, which we are carrying for several hardware iterations since more than 5 years ago. We have all the source code, most of it nicely documented. As the product is actively ...
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1answer
353 views

Encryption (AES-128) in automatic meters reading

I have theoretical questions about encryption when there's a lot of devices involved. Specifically it's about reading meters (water/gas/heat meters). Here's some introduction. I was trying to read a ...
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0answers
175 views

Dark Souls 2 String Encryption?

I'm tryin to RE dark souls 2. But, the strings are f***** up. I tried searching for "DARK SOULS II" which is the name of the window. No luck. I think it uses some encryption method (I've checked ...
0
votes
2answers
443 views

Android App's hardcoded local keystore password r3versing

Novice Android security researcher here. Recently I was tasked with the task/challenge of exposing a certain app's hardcoded local keystore password. I've decompiled it with JEB2 and obviously within ...
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0answers
126 views

Decrypting/Decoding encrypted/encoded data

I'm trying to increase the interoperability of some database software. The database can write and read "stored SQL queries". I wanted to figure out the format of these SQL queries so I can build them ...
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votes
0answers
95 views

encrypted awkward PNGs

I'm trying to read a bunch of image files from a chinese game, but most part of the .PNGs are somehow "impossible" to open. Checking some contents on .JAVA files, i found some encrypting and ...
0
votes
1answer
95 views

Finding out hash type having initial string and hash

I am a part of community dedicated to modding videogames. We've are having troubles identifying hash type. What do we have: A list of text strings and hex representations of their hashes - http://...
2
votes
0answers
261 views

What encryption/compression is this, and how to encode/decode from it?

I've been trying to reverse engineer an Android app's communication protocol using a combination of Xposed and Packet sniffing. Most of the packets the app sends have this header set: Content-Type: ...
0
votes
1answer
223 views

Is this anti-tamper solution fool-proof?

https://libreboot.org/faq/#intelme Introduced in June 2006 in Intel's 965 Express Chipset Family of (Graphics and) Memory Controller Hubs, or (G)MCHs, and the ICH8 I/O Controller Family, the Intel ...
1
vote
1answer
172 views

Which encryption/decryption algorithm is used in Synology Cloud Sync format 3.0 session key and data encryption?

Background: Based on general information in a whitepaper from Synology, I have reverse engineered the specifics of their Cloud Sync encryption algorithm; see synology-decrypt for details. In this ...
4
votes
1answer
1k views

Having keys and binary, how do I reverse/decrypt a stream encryption?

I would like to ask if you have any idea or approach to reverse engineer a decryption algorithm to find the opposite encryption function. I do have all required keys and fields and of course the ...
3
votes
1answer
370 views

How can I determine if a piece of code is an encryption algorithm?

I am trying to reverse engineer a malware, and came across a piece of code that I suspect is an encryption/decryption procedure, however I do not know for sure. I can recognize that it extracts its ...