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votes
1answer
46 views

Why rijndael.key value is different with rijndael.iv?

someone can tell me how rijndael works? for now i need to handle key and iv generated from C# (using rijndael + rfc2898derivebytes) to match with CryptoJS code snippet of C#: byte[] saltArray = ...
0
votes
2answers
254 views

Understanding AES Keys and Passphrases

I am trying to get my head around how AES works and in particular I have queries around the key generation and 'passphrases'. My understanding is that AES has a 128 bit block size but the key length ...
2
votes
1answer
143 views

Windows BitLocker- Is the drive Password the same as the Key used by AES to encrypt the drive?

I am using BitLocker on my Win10. I encryted my usb drive using my Windows BitLocker with a strong password. I know that Bitlocker uses AES-~256 bit key for encryption. My question what is the key ...
0
votes
1answer
68 views

Can Honey Encryption be used for CAN bus security? [closed]

AES encryption was one of the best encryption techniques used but it had a major disadvantage that it cannot handle brute force attack. Hence honey encryption was introduced which can handle brute ...
3
votes
1answer
149 views

How should I share the key of the AES algorithm in each client?

My doubt would be the following: How should each client know the encryption key? Using the AES algorithm. (or the best way): Save it in a file encrypted by password? Save it in a DB? Send it over ...
4
votes
4answers
510 views

Can I use a user's password hash as the AES key to make a one time token?

I want to make a one time token that users use to reset their password. The token should be invalidated once it is used, is it safe to use their currently hashed password as the aes key to encrypt the ...
2
votes
1answer
67 views

How to use login details to make a key for AES encryption and decryption

I have recently starting looking into AES encryption for a side project. I am researching this till now so if there is something wrong about my concept please correct it. According to me If i want to ...
0
votes
1answer
475 views

Decrypt AES 128 CTR with the IVs (counter) but not the key

I have the encrypted files, the random IV for each encrypted files and the counter increment function but I miss the key. Is there anyway for me to decrypt the files?
0
votes
1answer
2k views

OpenSSL: what's the difference between -kfile and -pass?

It seems both -kfile and -pass can be used to encrypt files with a 2048 bit keyfile? I don't understand the difference between the two methods: $ openssl enc -salt -aes-256-cbc -in inputfile.txt -...
1
vote
2answers
271 views

AES-256 decryption after key destruction. Possible or not?

Can AES-256 be decrypted if after the encryption process you destroy the key that must be used to decrypt the data, is it possible?
1
vote
1answer
11k views

How can I use openssl to decrypt AES-encrypted data using the key and initialization vector?

I am attempting to follow the example in this question: Where is the salt on the OpenSSL AES encryption? but I'm having some trouble decrypting using the key and initialization vector. When I ...
5
votes
1answer
299 views

TLS1.2 AES 128 CBC Encrypted Data size

I know that TLS ciphers such as TLS_RSA_WITH_AES_128_CBC_SHA transmit data as shown. From my understanding, the ciphertext must be a multiple of the block size, which in this case is 16 bytes. However,...
6
votes
1answer
7k views

How to encrypt data in frontend/backend with a key that is not stored anywhere and is only known to owner?

I have read bunch of answers and tutorials on how client side cryptography is not a good idea because of many reasons listed mainly in Javascript Cryptography Considered Harmful article. Some facts ...
3
votes
2answers
477 views

Can AES and SHA-256 outputs with the same inputs be used to break each other?

An abstract representation of my question looks like this: byte[] encrypted = AES.Encrypt(bytesToEncrypt, password); byte[] hash = SHA256.Hash(password); If an attacker obtains the values of both ...
-1
votes
1answer
2k views

AES-CBC then SHA vs AES-GCM for encrypting and authenticating a web token

I am trying to have something like JWT but kinda ad hoc and encrypted. The token itself is simply a stringified JSON that contains the user id and unix timestamp. Now, I tried to use AES-128-GCM, ...
0
votes
2answers
335 views

Is there a difference between encryption keys and encryption certificates?

Learning about cryptography. Experimenting with attacking the algorithm it's self. My question regards vocabulary basically. Are encryption keys and certificates the same thing or are they different? ...
1
vote
1answer
332 views

Is this usage of AES-CBC dangerous

Imagine that an attacker knows: A correct ciphertext. The algorithm: AES-256-CBC. The implementation: openssl CLI. The IV. The HMAC-SHA-256 of the ciphertext. But does not know the key (let's assume ...
0
votes
1answer
181 views

Is it safe to include the IV at the end of a hash?

I have a PHP function I have written that uses a 64 bit binary string and a random initialization vector to encode data using the following basic principal: $encrypted = openssl_encrypt($...
6
votes
1answer
628 views

Why does WannaCry use different AES keys to encrypt different files on host?

I have a question after reading the discussion here: Ransomware encryption keys So I understand the process of WannaCry encryption now, thanks to the accepted answer given by the community on the ...
0
votes
1answer
106 views

Why does setting cipher text to 21 characters mean plain text is nothing in AES256

Let's say I have the following where k is any length string If I do the following var p = aes256.decrypt(k, 'XXXXXXXXXXXXXXXXXXXXX'); The value of p will always equal nothing. Can this please be ...
3
votes
2answers
532 views

Properly encrypt using AES-256 in CBC mode?

For the purpose of the tool I am currently writing, I need to perform some AES encryption/decryption on some input. It's like a pipeline: you feed it data, it runs the algorithm and pass it out to the ...
3
votes
0answers
90 views

How dangerous is it to transmit the last N bytes of a datagram in plaintext?

I'm developing software for a university satellite project, and am currently working on the communications protocols. Here are the restrictions: Radio packets should be assumed to be no larger than ...
0
votes
1answer
107 views

Strength of below aes encryption

Need to store encrypted user code in our database and get the decrypted form in return. Using the standard node module crypto to do so. Wanted to understand the strength of below encryption in terms ...
2
votes
1answer
318 views

What reason do we have to believe that AES is unbreakable? [closed]

I'm learning about AES, and I haven't been able to find any intuition or justification about why we expect AES to be difficult to break. How can we be confident that there aren't techniques for ...
0
votes
0answers
89 views

Is there a good way to use to find out how this was encrypted [duplicate]

Ok, so this is a very basic cryptography question. I have captured a message from an Android app to a server. I believe this app may be stealing information from the phone it is on so I'm running it ...
2
votes
1answer
133 views

Is AES vulnerable if the plain texts share a known format?

AES encryption, if done correctly (secure mode; random IVs for every text; ...) is considered secure. Does this change if the plain texts have well-known formats? For instance, say we encrypt JSON ...
0
votes
1answer
272 views

Envelope formats to store (symmetric) encrypted text

We have decided to use AES to cipher user data. So for every data chunk we have the crypted text along with the SALT. Now we have to store both of them in the database and we do not want to separate ...
1
vote
0answers
444 views

Are there any DUKPT / AES standards or recommendations?

Are there any standards or industry practices with respect to the implementation of DUKPT with AES (as opposed to DUKPT / TDEA which is covered by ANSI X9.24-1:2009)? Understanding that DUKPT is a ...
1
vote
1answer
136 views

User login credentials used for file encryption

A system I'm implementing requires a user to create a single user, with a single login password. I want to have a single password for the system, and not require multiple different password entries ...
2
votes
1answer
432 views

How to Combine RSA and AES for Steganography Project [closed]

I wanted to have some knowledge about cryptography and steganography so I decided to write a steganography application with using LSB technique and for message encryption I wanted to combine RSA and ...
1
vote
2answers
548 views

Are disabling TLS 1.0, enabling RC4 or using TLS1.0 with AES only, the only ways to mitigate BEAST server-side?

I understand that BEAST is very hard to exploit and mostly fixed by modern browsers already. Also, enabling RC4 will introduce other risks. So, if you still want to mitigate the almost impossible ...
1
vote
0answers
36 views

A query with message block and gray code in LightMAC

In lightMAC the message is divided in to M[1] M[2] and so on eg: M[1]M[2]···M[l] ←− M If we consider AES block cipher 128-bit then I am wondering is the size of individual message block is 128-bit ...
22
votes
5answers
4k views

Why did TLS 1.3 drop AES-CBC?

I was watching this video about TLS 1.3: "Deploying TLS 1.3: the great, the good and the bad (33c3)" and was somewhat surprised to see that in their effort to provide "fewer, better choices" they ...
1
vote
3answers
4k views

Is it possible to combine RSA and AES? [closed]

I'm working on a new project that encrypts folders on my personal computer.No sending of files are involved(networking). It is only for protection and security. Is it possible to combine RSA and AES ...
4
votes
2answers
279 views

Is it secure to use unique prefix for each dataset, instead of using IV (in AES)?

In continue to my question here: How to prevent user guess the key (password), if he have access to all the data (except the key) I thought, that instead of using sepreate IV field for each SSN (for ...
1
vote
2answers
249 views

Are there any flaws in two step (RSA + AES) key exchange and secure channel setup?

To setup a secure channel with server I use the following setup in my application: 1.Generate a random AES key and random IV 2.Encrypt AES Key, IV and client credentials with RSA public key 3.Send ...
9
votes
2answers
578 views

The reason of using XOR operation in cryptographic algorithms

I notice that some cryptographic algorithms involve using XOR operation with the key (Even AES uses XOR to derive the round keys). My question is why specifically XOR? How about OR or NAND or some ...
0
votes
1answer
61 views

Is it insecure to use an IV based on the key?

If I feed AES an IV generated by MD5 using the key, will it cause a security risk? I understand that MD5 can be cracked in a sadly short amount of time, but will that effect the integrity of the ...
1
vote
3answers
3k views

Bruteforce decrypt xml file without knowing file content?

I am trying to decrypt an .xml file, but I do not know what it contains. What I do know: starts with 6 character alphanumeric passphrase passphrase is hashed by md5, or SHA1/2 AES128/256 encryption ...
2
votes
0answers
94 views

Is this a valid approach for multi-sign?

Requirement: An "arbitrary text" should be encrypted, and keys distributed among 3 people, atleast two keys are needed to unlock. Here is how I plan to do it, please let me know if I'm missing ...
0
votes
2answers
9k views

Encryption - RSA vs. AES

I have a question regarding encryption and whether to use symmetric or asymmetric encryption. The idea is to implement a form of data encryption in a variety of software. This data will be exchanged ...
4
votes
2answers
401 views

Is is possible to shuffle an AES ciphertext without owning the key for it?

I would like to know if it is mathematically feasible to change an AES(CBC) ciphertext and IV without owning the key, so that the ciphertext would look totally different while still decrypting to the ...
0
votes
2answers
216 views

Which of AES modes are safer and faster for transferring data over the network?

I have using Crypto++ in Qt and use of AES Algorithm for encrypting files. I know about AES modes and their applications. I have use of StreamTransformation method for encrypting files in CBC and EAX ...
2
votes
1answer
807 views

Choosing Key and IV in AES-256

I am working on a real-life project for a firm. I have to encrypt data using AES 256 as per specification. I want to know how are the key and IV are really chosen in real world projects. /dev/urandom ...
2
votes
2answers
240 views

Is it secure to use a part of the key as IV in AES?

I seen a lot of AES implementation samples wide spreaded over the Internet in almost every language I can recognize. There is one difference that I reflect to be repeated between all. Some of them ...
5
votes
1answer
545 views

Which block cipher should be used in TLS 1.2 (while keeping 1.3 in mind)?

I have been looking a bit at the various block ciphers for TLS. As everyone should (pipe dream) have migrated to TLS 1.2 by now it should be considered how to prepare for TLS 1.3, when it has been ...
1
vote
1answer
529 views

AES step by step

I can't seem to find an AES tutorial that starts from Unicode to Cipher text. All of the tutorials I found starts with 128 bit block already. Also, where do I start or what topics do I have to start ...
9
votes
2answers
5k views

Can I use SHA-512 hash as AES key?

I want to combine hashing and encryption for better security. So can I use a hash key generated from SHA-512 as a key in AES. For example, I have a password "secret", I calculate SHA-512 hash for it ...
0
votes
1answer
128 views

How to make a good choice between Symmetric and Asymmetric [closed]

Here and there and read a lot of articles and blog posts titled "Difference Between Symmetric Cryptography and Asymmetric Cryptography". But inside of them they are answered "What is Symmetric ...
2
votes
2answers
724 views

How can I create a secure random key for AES?

I need to generate a lot of shared keys for an AES method which uses in various condition, my concern is how can I generate unpredictable keys? I've had some research on Cryptographically secure ...