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.

Filter by
Sorted by
Tagged with
0
votes
1answer
53 views

PBKDF2 hash over PBKDF2 key derivation

Imagine an app where any user provides a username and a password. This password is used to generate a 'strong' encryption key (for AES encryption) with the PBDKF2 key derivation algorithm. This ...
0
votes
0answers
5 views

How to double the AES keysize in keepass? [migrated]

keepass is open source on github right? Is there any way to "append" its existing AES256, double the key size, make the program support AES512? What are ways to achieve that result Thanks
7
votes
3answers
288 views

How does Widevine, FairPlay, and other DRM's work under the hood?

I am trying to understand how DRM works under the hood. There doesn't seem to be much information about it on the web so I figured I would ask here. After some attempted research, I found it ...
3
votes
2answers
145 views

Are ECB and CBC modes of operation generally insecure?

In some Java code that I'm reading, I stumbled over the following encryption algorithms passed to the Cipher.getInstance(...) method: AES/CBC/PKCS5Padding DESede/ECB/PKCS5Padding RSA/ECB/PKCS1Padding ...
10
votes
1answer
315 views

What gpg defaults can be improved, when performance is not an issue?

gpg has some preset default settings, which I assume were selected as a compromise between speed and security. I understand that these are good enough for most people. But, in a situation where speed ...
1
vote
2answers
55 views

AES Traffic Security Assesment

Assume we have only access to the traffic between two module (Hardware, Software, ...) and These modules communicate with SSL (PSK). Is it possible to assess AES encryption of this traffic? some ...
0
votes
0answers
51 views

Is this symmetric key system secure?

I am creating a secure network data transfer system, and would like to know if there are any obvious flaws in this scheme. Secrets The secret is a password that is known to both clients. This ...
1
vote
2answers
158 views

Required a simple guide for secure messaging application

For my personal research, I have to create a messaging app, but security is only important part of application, security from MITM (man in the middle attack), at device end, and at server level. (note:...
0
votes
0answers
7 views

AES Key Derivation algorithm [migrated]

I need cryptography advice regarding this issue. Kamus is a service that encrypts secrets for applications running on Kubernetes. When using AES (actually, Rijndael) symmetric encryption, Kamus uses ...
2
votes
1answer
84 views

Why does the NodeJS Crypto docs use CBC instead of GCM for RSA key-pair?

I have read that GCM is almost always more secure than CBC when implemented correctly. However, in the documentation of NodeJS, CBC is being used as an example instead. The key-pair will be stored ...
2
votes
1answer
165 views

OpenSSL 1.1.1b warning “deprecated key derivation used”

We have a homework assignment to encrypt the famous Tux.ppm using AES with ECB and CBC mode. We have to show and outline how insecure the ECB mode is... So is there any way to ignore this warning? **...
0
votes
1answer
94 views

Can killerbee bypass AES-128 security?

I found information about KillerBee which sniffs Zigbee networks. Here is the tutorial: https://www.willhackforsushi.com/presentations/toorcon11-wright.pdf My question, is since Zigbee Xbee can use ...
2
votes
2answers
88 views

Should I chunk or not for AES-GCM file encryption

New to file encryption. Need to use AES-GCM for file encryption, can't change the alg. Heard about the max plain text size should be 64GB with same key and IV pair. Environment is python 3 with ...
2
votes
2answers
433 views

Does knowledge of data structure compromise AES encryption?

I'm considering encrypting a series of TAR archives using AES. Something I'm concerned about is the TAR format being quite predictable regarding field content and block sizes: Each file object ...
1
vote
1answer
57 views

First setup security protocols (key transfer) in not-secure environment

This question might very well be more a confirmation than anything else, but I'm breaking my head over a problem I try to solve. I hope someone can either confirm my thoughts or tell me something I'm ...
1
vote
1answer
96 views

Will using CTR mode with unique IVs, but only one password for encrypting multiple files, leak data or keys?

I'm working on a project to encrypt many files with a single password. The steps I will employ to encrypt the files are: user will execute a command similar to tool --encrypt --recurse directories/...
1
vote
4answers
448 views

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 ...
0
votes
1answer
62 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 = ...
1
vote
2answers
96 views

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 ...
3
votes
1answer
155 views

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 ...
0
votes
0answers
40 views

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 ...
0
votes
1answer
56 views

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,...
3
votes
3answers
236 views

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 ...
0
votes
0answers
89 views

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 ...
2
votes
0answers
141 views

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: ...
1
vote
1answer
660 views

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 ...
2
votes
1answer
113 views

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 ...
0
votes
0answers
19 views

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 ...
3
votes
2answers
138 views

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 ...
1
vote
1answer
106 views

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 ...
1
vote
0answers
50 views

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 ...
1
vote
1answer
78 views

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 ...
0
votes
2answers
464 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 ...
0
votes
2answers
210 views

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 ...
2
votes
1answer
96 views

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 ...
1
vote
1answer
127 views

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 ...
1
vote
1answer
132 views

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)...
0
votes
0answers
108 views

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 ...
1
vote
1answer
231 views

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 ...
1
vote
0answers
51 views

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 ...
2
votes
1answer
175 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 ...
4
votes
1answer
122 views

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 ...
1
vote
0answers
112 views

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....
5
votes
5answers
440 views

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 ...
1
vote
1answer
179 views

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 "...
0
votes
1answer
83 views

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 ...
1
vote
1answer
218 views

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 ...
1
vote
1answer
369 views

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 ...
0
votes
0answers
48 views

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 ...
1
vote
0answers
72 views

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 ...