Questions tagged [aes]

The Advanced Encryption Standard (AES) is a symmetric-key encryption standard adopted by the U.S. government. The standard comprises three block ciphers, AES-128, AES-192 and AES-256, adopted from a larger collection originally published as Rijndael.

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What are the actual merits of Galois/Counter Mode?

GCM (Galois/Counter Mode), in particular in combination with AES, has been a de-facto gold standard for years. Encrypt and authenticate in one step, that's just too awesome, and terms like AEAD work ...
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Data too large for key size while trying to sign then encrypt

I'm not very experienced in the security field, but I'm trying to sign then encrypt a large folder in order to deal with software updates in some machines that will be offline. I've thought about ...
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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 = ...
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Why are cryptographically secure random number generators required for shared keys?

As I understand, key exchange for secure communications like TLS has a client take a server's public key, generate a random AES key and send that as a shared key for further communication. The key is ...
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An alternative for /dev/urandom

I like to overwrite my harddisk with random data. Since /dev/urandom as source is too slow to overwrite a large amount of data in a reasonable time, I'm looking for a good alternative. These two ...
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What should the hamming weights be between every iteration of AES?

I have an assignment where I have to print out the hamming weights between every iteration of AES's diffusion steps and I have been getting a maximum weight on every iteration, but I can't seem to ...
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does BouncyCastle implementation of AES-256-CBC meet requirements: “128-bit IV”, “PKCS7 padding” and “HMAC verification”

I'm writing an app for a client and part of the client's encryption requirements for use of AES-256-CBC are: "128-bit cryptographically random initialization vector" "PKCS7 padding" "HMAC of encrypted ...
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What if the attacker tamper the IV used in the block cipher CBC mode?

I am a newbie to block cipher and when learning the CBC mode, I start to understand that an IV is being used in this mode and also will be transferred to the message receiver. So here is my question,...
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Is safe to use AES-256 to encrypt data with small variations?

I have two nodes that need to communicate, A is sending data to B. We just assume that AES-256 key is already shared across the nodes. The only data being sent from A to B are a few bytes commanding ...
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How is a cryptographic key used as a password when using WiFi? [duplicate]

I have recently come from a post and the accepted answer described the password as a cryptographic key. I have an understanding of RSA, AES and uses of it such as digital signatures however I fail to ...
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Is using AES secure for password managers?

I'm developing an application that automates processes. The user connects to many accounts that the application uses then passwords are encrypted using AES. An example algorithm looks like this: ...
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Decrypt file using Key and Initialization Vector in Linux

I am Salesforce developer but new to the Security World as well as Linux. We encrypted a file with Key and initialization Vector in Salesforce(only symmetric encryption is possible in Salesforce). No ...
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is it safe to AES encrypt the RSA private key and storing it in the database

i'm building an app that really needs encryption of this type , my question is it safe to store the aes encrypted RSA key in the database ? here is how i encrypt the key : i generate a random 256 ...
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60 character hex encrypted value with 32 character hex seed [duplicate]

Attempting to recover lost admin passwords from an old industrial control system database. We believe these have been encrypted rather than hashed (at least we know password version 0 for this system ...
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Using AES to securely store sensitive pictures

I'm not experienced with encryption at all, so please bear with me. My use case: I'm working on a membership management web application to be used by a small organisation. When someone becomes a ...
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Is it safe to use 2 password derivation functions to one password?

The example I'm working on is this: i store the user password using Argon2 in my database and then use PBKDF2 to derive an AES key from the user password , and store only the salt used in PBKDF2, i ...
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iStorage DatAshur PRO AES-XTS 256-bit - 15 Digit Pin Time Til Brute Force

I am looking into the above encrypted usb drive, however, my concern is that its only a 15 digit pin of numeric characters, and I am not sure how to do the math on time til brute force... Is a 15 ...
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What should I use to encrypt data between a centralized server and multiple devices running NodeJS?

I have a centralized server and DB that each of my devices polls every ten seconds. The centralized server may respond with a list of "active jobs", which the devices will then run. I need to ensure ...
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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 ...
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Why do Browsers in their TLS1.3 Client Hello do not request for CCM ciphers?

As per TLS 1.3 RFC 8846, following 5 ciphers are supported. TLS_AES_128_GCM_SHA256 TLS_AES_256_GCM_SHA384 TLS_CHACHA20_POLY1305_SHA256 TLS_AES_128_CCM_SHA256 TLS_AES_128_CCM_8_SHA256 ...
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Which KEK can wrap AES, RSA and ECDSA keys securely?

If I have AES256, RSA4K and ECDSA-512 keys as CEKs, which I need to securely store, what KEK can I use to securely wrap these without reducing the bit strength? I am aware that an AES256 key can wrap ...
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Is double encrypting with AES safe?

Is it safe to encrypt twice with AES, with any mode? Are any combinations of AES, e.g. AES with XTS and AES with CBC, or twice with AES and XTS, more unsafe than just having it encrypted once? I know ...
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Is it secure to store a cryptographic key in a class member variable?

Consider an application that runs locally on a Windows PC. The application uses a local folder for reading/storing encrypted data (i.e. images). A user logs in (authenticated from a local encrypted DB)...
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How secure is Microsoft's Office and LibreOffice's password protection?

AFAIK both Microsoft Office and LibreOffice have features to add passwords to protect the content. In general, there are two ways: protect from editing/changing (without a revision at least) protect ...
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Can we write both encrypted text and plain text to the same file?

We have a requirement from customer to write payment transaction information to a text file. Of many lines of data per transaction, only one line contains cardholder information, which needs ...
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operation mode of an encryption algorithm

The operating mode of an encryption algorithm, especially a block cipher, describes how to use the encryption function for a single block repeatedly to encrypt or decrypt an entire messages with a ...
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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 ...
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how much is AES GCM's security affected when not using unique IV's

I've read some articles and tutorials about AES GCM and was using this cipher for one of my java-projects, so let's say I know some basics. I read that you should use an IV-length of 12 bytes which ...
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Why does OpenSSL fail to decrypt when the key is too large?

I have the following groovy script: cmd1 = "echo ${really_long_key}" ssl_cmd = "openssl aes-256-cbc -md md5 -nosalt -a -pass pass:${encryptPassword} dec" def process = cmd1.execute() | ssl_cmd....
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AES256 with 128 bit key

A popular zero-knowledge file sharing site uses a 128-bit master key for encryption. However, they claim to be using AES256. When questioned, they explained the master key is widened using PBKDF2 ...
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Null IV for AES CBC vs GCM [duplicate]

If we agree that using a null IV for AES in CBC and GCM mode is not a good idea, but for whatever reason one is encouraged to use a null vector for several messages using the same key, is there a "...
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Public key encryption confusion

I'm learning Linux, and currently SSH. But there are details that I don't really understand. I've seen and understood how Diffie-Hellman key exchanges work from a mathematical point of view, but what ...
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Cross platform OpenSSL aes encryption

I encrypted a file by using the following command from a stackoverflow answer: openssl enc -in file_name -aes-256-cbc -pass stdin -out file_name.aes; I can decrypt this file by running: openssl enc ...
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1answer
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Decrypting AES-128-CBC leads to first block being correct, the rest corrupt

I'm currently investigating a piece of software which encrypts it's files with AES-128-CBC. From disassembly it is truly known that the algorithm used is correct (log messages plus calls to the ...
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Why boxcryptor use hybrid cryptosystem to encrypt files

I do not understand why they need asymmetric key encryption, if the client does not use the public key. As far as I understand it, the user password is used to decrypt the private key and no public ...
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When using openssl to encrypt a file, how would I create a key made up of specific letters? [closed]

I want to create a 128bit AES key made up of specific letters. I think I would need to use something like openssl genrsa -aes128 -out privkey.pem or openssl genrsa -out privkey.pem but I'm not ...
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encrypting TCP and UDP with self signed cert

I don't have much experience in computer security and I am developing a server for a project. I'm using a tcp connection and UDP packets for some real time data transmission. I want both of these ...
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1answer
201 views

Safe encryption algorithm that works with files bigger than 68GB

In my Java application, I used AES/GCM/NoPadding algorithm for encryption, however it throws an exception when I try to encrypt files bigger than ~68GB. From what I read, it is limit of data that can ...
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Are there any known examples of companies who were successfully breached using POODLE, BEAST or SWEET32?

When this was first announced back in 2014, Brian Krebs reported on how much of a threat these kinds of birthday attacks were, but I have not been able to find a case study of a successful breach. Is ...
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Length of a stretched gnupg passphrase that is comparable in strength to an unstretched string of 256 random bits

Assume that we want to encrypt a file with gnupg using AES-256 as the encryption algorithm. (Hence, symmetric encryption.) In this mode, gnupg requires a passphrase from the user. I understand that ...
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Decrypting gpg2-symmetrically-encrypted files using non-gpg2 tools

If I encrypt a file using gpg2 and specifying AES256 as my encryption algorithm, can I decrypt it with tools other than gpg2? More generally, does the fact that one tool used AES256 for encrypting a ...
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Is AES-256 not the best decision for mantaining performance in a Datalake?

I'm worried about performance in a Data Lake used for Data Science purposes. I need to encrypt confidential data and, because of definitions I won't dive into here, the algorithm to fulfill this ...
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want to know best way to my case is to encrypt the UART communication channel? [closed]

I have device connected to scooter it’s 4- wire uart communication. My fear is some can read the ascii data and send the at commands and unlock my scooter and steal the scooter. I want to secure the ...
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Is GPG's AES encryption that much stronger than its RSA headers? [duplicate]

Correct me if I'm wrong at any point of this questino. I understand that AES is a lot cheaper to compute than RSA (or any form of asymmetric encryption) and that that is why GPG and similar programs (...
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1answer
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AES, RSA, ECC Key size [closed]

It is generally said that 2048-bit RSA keys are roughly equivalent to 112-bit symmetric keys and 2048-bit RSA keys are "sufficient for commercial use until around the year 2030" (https://security....
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How to combine symmetric and asymmetric encryption to encrypt large files?

I understand that it is possible to combine symmetric and asymmetric encryption in a way that makes use of the performance of symmetric encryption, and also getting the benefits of being able to ...
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Why is authentication impossible with CBC mode?

Suppose I have a protocol where fixed-length messages (1280 bytes, no padding) are encrypted with AES in CBC mode. I want to put some data in the message body to verify that the message is authentic. ...
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What is the impact of the reported weak IV in 7 Zip?

It has been reported that 7 Zip generates IVs in a weak manner. What is the actual impact of this? I'm asking about historical Zip files that I've sent. I've no plans to use 7 Zip going forward until ...
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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 ...
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AES Keys Storage for encrypting hashes of SAM file in Windows 10

Hashes of user account passwords in Windows 10 (like in older versions) are stored in SAM file. Using standard utility pwdump 7 for getting these hashes gives following result: ::LM hash : NTLM hash ...