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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why does IV not need to be secret in AES CBC encryption?

According to Wikipedia, the initialization vector (IV) does not have to be secret, when using CBC mode of operation. Here is the schema of CBC encryption (also from Wikipedia): What if I encrypt ...
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Why is 128bit AES considered very strong but 160bit SHA depreciated?

Why is 128bit AES considered very strong but 160bit SHA 'insufficiently secure'? Google/chrome/browsers seems to drop support for SHA1 SSL certificates. I assume it's more simple to calculate SHA than ...
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1answer
34 views

Does use of fixed padding pattern compromise AES-ECB

I'm working on an application where AES-256-ECB has been specified. It has been asked that a fixed pattern is included at the end of the message to allow the decoding end to ensure the decryption has ...
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1answer
36 views

Store password ciphers using Powershell ? DPAPI/AES

Hi and sorry if it is in wrong place I am making a script that requires to have a lot of server's IP and their passwords stored into a file. I wanted to use Windows DPAPI, but as we can easily ...
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5answers
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Is this RSA/AES combination good?

The team of developers I am part of is trying to develop a safe way to exchange sensitive data between a server and mobile devices. We have come up with the following algorithm: Device generates ...
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0answers
46 views

How does Signal Protocol, used by `whatsapp` Works?

I want to understand the process of The Signal Algorithm, I have google it, but unable to find any good Article or tutorial. I want to understand the basic definition and functionality of The signal ...
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1answer
80 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 ...
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2answers
1k views

Designing my own HSM using an Arduino

I am attempting to build from scratch something similar to Apple's Secure Enclave. What I've done is use an AES library for the Arduino to create a security appliance. A random crypto key and the ...
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2answers
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Different performance of openssl speed on the same hardware with AES 256 (EVP and non EVP API)

If I run openssl 1.0.1e like this : $ ./openssl speed aes-256-cbc (i.e without EVP API) Doing aes-256 cbc for 3s on 16 size blocks: 14388425 aes-256 cbc's in 3.00s Doing aes-256 cbc for 3s on 64 size ...
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2answers
141 views

Is it safe to reveal AES encrypted password?

Please correct me if any of my statement is incorrect. It is probably more good practice to not show any hint of the password. However, AES encrypted passwords by itself cannot be used to decrypt ...
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2answers
6k views

How is WhatsApp sending end-to-end encrypted messages in push notifications?

WhatsApp implemented end-to-end encryption (whitepaper) in their latest update. How is it possible for WhatsApp to send push notifications with message contents to the Apple Push Notification ...
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0answers
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AES 128 CBC in Python, cannot generate same cipher text by decrypting and encrypting again [migrated]

I am reading binary data from a .db file. It consists of a master-key, IV and some values. The first encrypted value is (say enc_val) with hex of 0abd4e92a8986ee1ae234e51f0783c79 After decrypting ...
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0answers
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Is there a key for AES-128, 256 etc, where cleartext equals ciphertext? [migrated]

Is there a key for AES-128, 256 etc, where cleartext equals ciphertext? (regardless of modes like chaining or ctr-cbc)
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1answer
150 views

How to wipe disks before encryption with dm-crypt if CBC or XTS is used internally?

First, please forgive me if I'm posting this question to the wrong community. Feel free to migrate this post to the right community if I was wrong. I'm quite new to whole disk encryption (but not ...
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2answers
827 views

How secure is AES-256-CBC with user provided password and initialization vector

From my understanding the IV is used as a previous block for the first block only. But since each block is used by the following this adds significant security is a IV is provided and not based on the ...
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1answer
333 views

I stored a copy of my KeePass database on a portable hard drive and I lost the drive. Should I worry about that?

I've been using KeePass for years, and I have a lot of accounts. I need to access them anywhere I work, so I store one copy of my database on a portable hard drive. The drive isn't encrypted. The ...
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1answer
67 views

OpenSSL key derivation

I'm trying to manually decrypt DTLS packets sent by OpenSSL. The cipher suite used between the server and the client is TLS_RSA_WITH_AES_256_CBC_SHA256 and my understanding is that the IV used by ...
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1answer
43 views

Stateless AEAD (AES-GCM) based tokens

I want to generate secure data tokens which can be shared with the client for uses like password reset, etc. which involves low storage overhead at server end. Ideally I am interested only in managing ...
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0answers
15 views

Authentication tag lengths of AES-CCM in TLS

I'm catching up on understanding some of the new cipher suites that are appearing in TLSv1.2 and will be making an appearance in 1.3. While looking through AES-CCM, I discovered that it offers a ...
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2answers
54 views

Diffence between AES-128 CMAC & AES-128 ECB/CBC?

Automotive standard for encryption use to talk about following algorithm AES-128 CMAC & AES-128 ECB/CBC. AES-128 CMAC use to provide Security service Authenticity AES-128 ECB & CBC used to ...
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1answer
85 views

Is webkey a reasonably secure authentication system?

I just created Webkey in the last couple days. It's built to do client-certificate auth without using the (in my opinion unusable) client-cert functionality built into browsers. It would allow ...
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2answers
50 views

Are any inherently insecure AES-CBC keys or key-IV combos known for properly generated random values?

This is mostly a theoretical question. I am using AES128 CBC to encrypt small files. Both my keys and my IVs are randomly generated per file using iOS's secure random value generation ...
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Android default encryption settings

Does anyone know how to change the Android default encryption settings? I want to use AES256, SHA2-512, increase the iterations to 100k and increase the salt to 256bits. Can I use dmcrypt to change ...
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1answer
95 views

Why does this key get Base64 encoded prior to use?

I wish to have my server encrypt messages to clients who have each provided the server with an RSA public key, as well as having the clients authenticate their messages to the server using their ...
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1answer
48 views

Is symmetric encryption with one time pre-shared key secure?

Suppose I have a secure channel between client and server, with proper certificate validation etc (actually, ssh session). I want to establish a secure connection between my own application on a ...
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0answers
27 views

when/how does an encrypted volume .dmg change to reflect the file system it stores

I'm trying to verify that storing a .dmg file stays encrypted while only the mounted file system is unencrypted (see here). My thought was to create a .dmg containing a text file, make a copy of the ...
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2answers
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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 ...
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1answer
29 views

OpenSSL_encrypt returning an incorrect cyphertext?

I am trying to use the openssl_encrypt function in PHP, this is my code: <?php $message = hex2bin("00112233445566778899aabbccddeeff"); $key = hex2bin("000102030405060708090a0b0c0d0e0f"); $method ...
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3answers
100 views

What is the benefit of adding data encrypting key then store it (encrypted) along with data

To protect user's sensitive data, I am considering the following 2 approaches: Create 1 data encrypting key (DEK) for each user, use it to encrypt (using AES CBC mode with a random IV for each ...
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2answers
46 views

How does KEEPASS store images, videos and attached documents/items? [duplicate]

I have read quite a bit about KEEPASS and how it encrypts passwords. However, the more I read about it, the more I find how it generates and stores passwords - the methodology provided as well as the ...
2
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2answers
36 views

Could I use a TimeStamp also as IV?

For an academic application, I use AES-GCM to encrypt my frames between 2 parties. To enhance security, and reduce the possibility of replay, I'd like to use a TimeStamp in my frame exchanges. But, ...
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0answers
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How to safely store the most recently used encryption password for subsequent reuse in an app?

Let's say I have a mobile app that can save photos inside password-protected AES-128 encrypted PDF files. For convenience, I want the user to be able to encrypt a file using the previously-used ...
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3answers
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openssl: recover key and IV by passphrase

A large amount of files were encrypted by openssl enc -aes-256-cbc -pass pass:MYPASSWORD Openssl should derive key+IV from passphrase. I'd like to know key+IV equivalent of that MYPASSWORD. Is ...
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0answers
22 views

Cryptography basics (in the context of AES256) [closed]

Bit of a noob question and a fair bit of Googling didn't help. I understand that the current encryption standard is AES256. A few questions 1) Is the point of this (and other encryption techniques) ...
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0answers
56 views

How to decrypt the my 1Password Vault without using the 1Password App?

I would like to know, how someone can decrypt his 1Password Vault without using the 1Password app. It should be feasible. Right? In a nutshel, My Master Password is the only "AES key" that my ...
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4answers
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When should I use symmetric encryption instead of RSA?

I'm currently using GPG RSA keys to encrypt binary files. Many people recommend using symmetric keys to encrypt large files, and then encrypt the symmetric key with a public key. At what file size ...
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2answers
151 views

Is AES 128 encryption weak for very small payload size?

If I have a payload of e.g. 8 bits and I want to encrypt it using AES 128, I will need to add some random padding to make the plaintext 128 bits long. Does this padding affect the security of AES?
69
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3answers
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Will quantum computers render AES obsolete?

This is a spin off from: Use multiple computers for faster brute force Here's at least one source which says that quantum computers are on the way to being able to break RSA in the not too distant ...
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3answers
4k views

Use multiple computers for faster brute force [duplicate]

I've watched Mr. Robot lately and can't stop thinking why it was so hard to decrypt files encrypted using AES encryption with a 256-bit key. Let us say the only method to find the key is through brute ...
3
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3answers
802 views

Calculate time taken to break AES key

A 256 bit AES key is required to be broken using the brute force method on a 2GHz computer. How long would it take to break the key in the best case and in the worst case situations? Assume that 1000 ...
11
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3answers
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Pitfalls of SSD encryption

Encrypting an SSD is a process that is sometimes warned should be done with caution. E.g. http://en.gentoo-wiki.com/wiki/DM-Crypt_with_LUKS mentions how the SSD may keep hidden space used for wear ...
4
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1answer
109 views

How secure is my software for file encryption with AES-256?

I'm working on a project to build software for file encryption with AES in Java, it's operation is quite simple, but I was wondering if it is really safe. The program prompts the user for a ...
166
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8answers
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Why can't the FBI read the key embedded in the iPhone's secure chip/ROM directly from hardware (silicon)?

As far as I understand, the 4 digit passcode is combined (in some fashion) with a key stored in secure read only memory (e.g. secure enclave chip or similar), where it is directly embedded into ...
3
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2answers
236 views

Am I encrypting and storing an array of user-details correctly?

I came up with a user-details-storing procedure that was, in the beginning, based on actual security-literature – but then I just kept writing without really doing all the cross-checking I should have ...
0
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1answer
40 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 ...
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1answer
71 views

FileVault 2 FDE and BoxCryptor are safe to use together or they have conficts?

Assuming that someone has a Mac and uses FileVault 2 FDE (256-bit AES key) and uses the BoxCryptor (256-bit AES key) for the clouds like Dropbox/GDrive/etc and or some other folders. FileVault 2 uses ...
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1answer
42 views

How is hash used with AEAD-based ciphers in TLS? [duplicate]

Look at this cipher: ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128) Mac=AEAD It uses AES-GCM for encryption and data origin authentication (according to RFC-5288), so no ...
2
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2answers
478 views

Practical steps for encrypting an encryption key for data stored in MySQL

So I'm working on my first project where user data is stored as encrypted using the user's password as (part of) the key. I have read many similar things about best practices, but the details seems to ...
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1answer
98 views

what is the best way to know if the entered decryption key is correct?

I was searching for a way to store the encryption key of AES_ENCRYPT and found a good answer here: where to store a key for encryption However, now I am trying to use "Type in the encryption key when ...
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2answers
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Is AES slower to encrypt than MD5?

Is this the right interperation of this diagram: http://www.cryptopp.com/benchmarks.html AES/CCM MiB/Second:61 Cycles Per Byte:28.6 MD5 MiB/Second:255 Cycles Per Byte:6.8 And does that ...