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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How to convert passphrase to AES256 key?

My plan is to convert a passphrase in UTF-8 ASCII-US to Unit8Array(32) then use it in: 256bitsKey = Unit8Array(32) from passphase iv = window.crypto.getRandomValues(new Uint8Array(32)); CryptoJS.enc....
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AES-256 without key stretching

It is not so difficult to create a password which is exactly 32 characters long. In this question - AES-256 Key Length Importance @Marc writes: you absolutely should not be using a password as the ...
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AES-256-GCM transfer IV and AuthTag

Question is for transfer encrypted data between two services (Like HTTP, GRPC or etc...) Can I transfer IV and AuthTag in plain, Is this approach secure? I have sample code in Node.js and I'm not ...
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How safe is AES 256bitkey encoded in HEX, Base64?

I am using CryptoJS AES 256 encryption: CryptoJS.AES.encrypt(realData, generateKey(passphrase), {iv: iv}); The secret is generated through: function generateKey(passphrase) { const salt = CryptoJS....
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If I use multiple different RSA public keys to encrypt a single AES key for distribution, how much does that degrade the encryption?

I would like to store encrypted AES-256 keys in a public location and give 100 different people access to the AES key by using each of those 100 people's public RSA encryption key to encrypt the AES ...
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Can I get AES CBC key from known plaintext, ciphertext, iv? [duplicate]

Long story short: I was using AES CBC PKCS5 on my image server, but I lost my keys (one key per image). I know the first 61 bytes (the original and the encrypted) of each image plus I know the IV, and ...
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How to correctly convert a bit key to string for aes 256 encrytion?

I am using CryptoJS AES 256 encryption: CryptoJS.AES.encrypt(string, secret); The secret is generated through: function generateKey(str) { const salt = CryptoJS.lib.WordArray.random(128 / 8); ...
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IV generation with RNGCryptoServiceProvider

I'm using RNGCryptoServiceProvider.GetBytes(new byte[16]) to generate IV's to use in AES (256 bits) encryption. For every record I encrypt, I generate a new IV. I'm also prepending each of these IV's ...
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Nonce in Aes-gcm AAD

I have some data which I'm encrypting using Aes-Gcm. Every time I have to encrypt the data, I generate a random nonce of the appropriate size, as well as an empty array for the tag data. In Aes-Gcm, ...
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Does using subkeys provide better protection in this instance?

I was thinking of implementing the following scheme for encryption of many independent files: From the password, which is given by the user, generate a master key using for example HMAC-SHA. From ...
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Reusing the IV, but not the key

There are a few questions on this site asking about reusing the same initialization vector for example for AES encryption under the same key, see for example this question. Now, let's not respect that ...
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Why encrypting with ECB block cipher mode provides different result?

I'm playing around with openssl command line to verify my understanding on block cipher mode. I read that ECB block cipher mode always encrypt the same text to the same output. AES operates on 16 ...
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7z “Copy 7zAES” algo brute force with 32 char password for when original file is available (QNAP QLocker ransomware) [duplicate]

As some in here might know, there is/was a ransomware attack going on worldwide that used 7z to encrypt all files <20MB for a ton of users world wide. Each user has a unique 32 char password (Upper ...
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In Algorithm: dh-ietf1024-sha256-aes128-cbc-pkcs7 where to get the IV?

I'm implementing dh-ietf1024-sha256-aes128-cbc-pkcs7 in golang and according to documentation I've managed to create the 128-bit key appropriate for AES (from my 1024-bit shared-key computed from my ...
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How to save AES Key in PEM file

I'd like to store a private symmetric key, aes-256, in a PEM file. My understanding is that usually these types of keys are derived using RSA/EC DH and there's no need to save them, but in my ...
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GoCryptfs on cloud

I read the audit docs on GoCryptFS website (https://nuetzlich.net/gocryptfs/threat_model/). There dragon has full information about the read write done in the gcfs partition, what does this mean and ...
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Hybrid Encryption: What is the format for storing the encrypted key and the cipher text together?

In the scenario of a hybrid encryption for which I use RSA (asymmetric) to encrypt the encryption key used with AES (symmetric) to encrypt my message, I need to store the encrypted key with (together) ...
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Get HLS decryption key from browser

How can I get decryption key for AES-128 encrypted HLS stream. In the m3u8 file, the URI for key leads to a file which is of 48 bytes which is encrypted. The stream is played by browser so it must ...
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Encryption/decryption at client or server side with hybrid cryptosystem?

I've read a lot of documentations about encryption in the last weeks and I think I now have a good idea of what system I will use for my project (standard hybrid cryptosystem using RSA/AES). However, ...
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Why does firebase encrypt with password hashes instead of storing the hashes?

I am trying to migrate off of firebase, as in doing so, you can export the hashes of user passwords. Looking at their algorithm, they do not store password hashes, but rather, they use the first 32-...
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Is using SHA256 to create 256bit secret key from bcrypt good ok?

I am trying to Use AES to store passwords for a password manager. For authentication I am already using bcrypt. As AES uses 256 bit Key can I use SHA256 to generate 256 bit key from hashed value of ...
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Key Exchange using RSA public key without a certificate

I want to share AES key using RSA. What is the recommended/widely used format for encrypting the AES key and its attributes with the public key? I know that PKCS#7/CMS enveloped-data allows encrypting ...
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Decrypt AES 128 encrypted file with a key file

I have a file which is encrypted using AES 128 and I have a key file whose size is 48 bytes. How can I decrypt the file using the key file? The key file has no extension, I opened it in notepad and it ...
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Why AES output has more size than my plaintext?

I have enciphered a vector of bytes that has 17 bytes in itself. However, When I try to enciphered with AES, AES output has a 32-byte size? What is happening here?
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Why is a password encrypted with AES and then sent back to the server together with the key with RSA (Instagram)?

I am trying to understand an encryption process on a website (Instagram). As far as I know, a public key is sent from the server to the client. Then the password is encrypted with AES_GCM_256 and ...
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Calculate AES-GMAC

I have a symmetric key and I have the data that needs to be authenticated. So one of the solution that I have in mind is to use the AES GMAC. I know there are other MAC's such as HMAC or hash ...
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Is the following a secure method for file encryption?

So the goal is to use AES-CBC-256 to encrypt the data in a file. To derive the AES key and IV pbkdf2 will be used to generate a 384 bit output using a given password and salt, where the first 256 bits ...
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Can password managers read my secure data? If no, how does sharing work under the hood? [duplicate]

All the popular password managers on the market advertise that they have AES-256 grade security. In a nutshell, the user has the master key and the password manager has the cipher-text. So the ...
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Which one to use AES : GCM vs CBC

I am planning to encrypt database fields using AES encryption. Now, this encrypted data will not transfer over the internet and will reside in our own datacenter only. From what I read, GCM mode ...
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Question regarding data encryption/decryption and sharing said keys with third party's

At work we have a pretty complex problem(for me at least) and I have no idea what a fitting solution would be. To give a bit of context, the company I work for is a data processor/provider for big ...
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Are there intrinsically weaknesses in accessing a same payload encrypted with different keys?

Assume we use AES256 to encrypt the same payload 100 times, each with a different key. An attacker gains access to the 100 encrypted payloads, and nothing else. Is there some way the attacker can gain ...
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Wrapped Key Encryption - Hide AES secret key in Javascript & Java

I need to encrypt some sensitive fields back and forth in browser and server, same goes for decryption, for this I am planning to implement AES algorithm, but the problem here is with secret key which ...
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With AES, does key format make a difference to security?

For context, I'm assuming the attacker knows the format of the key. Do these two keys have the same strength, or by leaving the hyphens in the key am I reducing the security by a partly-known-key ...
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On what basis to create Data Keys

For PII, we have to encrypt some columns in our DB(All of our infra resides on our own DC, not using any cloud provider). Now roughly what we are doing is Created a CMK at AWS. Generate Data Key ...
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Symmetric encryption - given plain text, produce cipher text without key

Suppose Alice and Bob are communicating using a peer-reviewed symmetric encryption algorithm such as AES-256. Bob possesses a private encryption key to decode messages from Alice, but Alice does not ...
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How to perform encryption/decryption in a RESTful system?

I'm not a crypto/security expert and have designed an architecture for encryption/decryption. I'm not sure if its full proof and want to know what people use as industry standard? I'm trying to ...
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Review of the design of Credentials Manager app

I want to make a mobile app that will act as a Credentials Manager and store all my access information for websites, credit cards, secure notes, and so on on the server encrypted with REST API. The ...
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How to securely design REST API for Password Manager app?

I want to create Password Manager where users can create their accounts and store website passwords. For the frontend, it will be a mobile app, but I need REST API as the backend data where the data ...
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how to encrypt and decrypt messages with more than one sender and more than one receiver?

I am creating a chat app. This app contains private messages and channels. These channels include more than one user. I want to encrypt messages using AES and to transfer the AES key to users of this ...
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Establishing safe connection in Java

In my Java project I'm trying to create a 100% secure method of communication between the method and the client. I used to use this process: Client: generates 4096-bit RSA keypair Client: sends public ...
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RSA key exchange

I want to create a message exchange program. These messages are encrypted with the AES key, and this key is encrypted using the RSA algorithm. When I send a message from User 1 to User 2, I need to ...
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Where and how to store admin account credentials for enterprise systems?

To my understanding, password-protected spreadsheets are not best practice for storing admin creds, whether it's a company of 5 people or a company of 50,000 people. In such a case, what are some best ...
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Reused key issue in Asymmetric Encryption

We all hear often about the reused key issue in block cipher. For example, for a picture being encrypted by the electronic codebook mode, we will still see the shape of the picture. https://images.app....
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Is there a standard approach for serializing an RSA encrypted AES key alongside the AES payload itself?

Diffie-Hellman won't really work here, since only one side has a public key, one side has the private. It must be this way to prevent decryption when the data is at-rest on one of the sides before ...
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Performance comparison between ed25519 vs AES

I found that AES has dedicated hardware on most machines. The question is can we use ed25519 to replace AES? Instead of using RSA to encrypt the AES key and then encrypt the data with AES, can we just ...
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Is AES statistically noise? Reliably so?

Suppose we want to store files in a way that has plausible deniability. Ie. we can deny the existance of those files. The approach is this: We allocate (or just use) a chuck of disk an initialize it ...
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Password relevance in key derivation function

I'm questioning the password used in a key derivation function, whether It makes sense to make it unique for every generated symmetric key and why
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Is there any point in using a non-null IV for AES-GCM if the key is only used once?

I understand that re-using a key without a unique IV is a deadly sin, but what if there‘s the guarantee that the key is only used for encrypting and decrypting one dataset? I was thinking about ...
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Format for data & key exchange/storage [duplicate]

Is there a standard format for storing/exchanging encrypted data along with the key needed to decrypt it (data is encrypted with a single use symmetric key and the symmetric key itself is encrypted ...
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AES-256 ESSIV in dm-crypt

I am playing around with disk encryption. https://gitlab.com/cryptsetup/cryptsetup/-/wikis/DMCrypt#iv-generators says: essiv: "encrypted sector|salt initial vector", the sector number is encrypted ...

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