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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AES-256 Decrypt a VHD File

I recently messed up with my McAfee Encrypted Laptop (2 Drives) and got MBR overwritten by Linux (Ubuntu). I used DETech CD on C: but after 2% it failed due to Bad Sector. Using a safety precaution ...
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61 views

Secure Software Architecture

I am designing a software architecture and i need some suggestion and clarification on few issues. This will be a server side RESTfull API for accessing data and multiple mobile/desktop client to ...
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2answers
51 views

Authenticated encryption (Symmetric encryption) for .NET applications [on hold]

Is there an implementation of Authenticated encryption for .NET applications? The AES API from .NET does not include mode such as GCM. In the documentation, I can only see insecure modes (ECB, CBC, ...
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133 views

Sending Encrypted Messages with Hybrid RSA, AES and HMAC SHA-256

Is this a Secure strategy for sending a large Encrypted Message using Hybrid RSA 2048, AES 256 and authenticated with HMAC SHA-256: Given the Alice already has Bob's RSA Public Key, Alice: ...
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2answers
61 views

Clarification about IV in PBKDF2 to generate encryption key

I've realized that the following implementation isn't truly safe: $pb = pbkdf2('sha256', $_POST['pass'], "enc_salt", 100, 100); $d = openssl_decrypt ($data['container'],'aes-192-cbc', $pb, true, ...
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48 views

What is the output length of CBC with zero input?

Given this formula for CBC encryption from 6.2 The Cipher Block Chaining Mode what is the output length of CBC if plaintext P is of length 0?
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4answers
1k views

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 ...
2
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1answer
48 views

Is a Fernet token's timestamp a security risk?

A Fernet token has the following format: Version ‖ Timestamp ‖ IV ‖ Ciphertext ‖ HMAC As the above shows, the timestamp is not part of the ciphertext, so anyone can read the time the token was ...
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2answers
70 views

Is it possible to construct a specific AES collision?

Suppose I have a plaintext message P, and I encrypt it using key K to get ciphertext C. It's trivial to find a different plaintext message P' and a key K' so that the encryption results in C: just ...
2
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1answer
68 views

How to implement encrytion/decryption system using IV between mobile app and web service

In my app we are going to send encrypted data to the web service. I am using the following code to encrypt and decrypt the data - public class DecEn { private static final String password = ...
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1answer
98 views

Is it insecure to provide a hash of an AES password?

I have made some software that encrypts and decrypts files using AES. I was wondering if it is safe to write a hash of the password to the file so that the program can check if a password is correct. ...
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36 views

A simple HMAC question

Suppose I use a key (and IV) to encrypt a piece of binary data with AES-256-CBC to produce the corresponding encrypted data. Suppose I then throw this encrypted data into HMAC-SHA512 using the same ...
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96 views

How to prepare FATCA data transmission files with open source tools [closed]

Here is the context: to transmit FATCA data to US IRS service the IDES protocol defines the following steps sign the XML Payload.xml file with enveloping signature, SHA-256 with RSA private key, as ...
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30 views

Why FATCA IDES “protocol” does not use RSA encrytion directly on Zip archive ?

Here is the context: to transmit FATCA data to US IRS service the IDES protocol defines the following steps sign the XML Payload.xml file with enveloping signature, SHA-256 with RSA private key, as ...
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2answers
199 views

How do cryptographic algorithms help hackers to bypass Antivirus software?

I was wondering how do hackers use cryptography for bypassing antivirus software. I don't have some deep understanding on how antivirus software works, but I know that every antivirus has base of ...
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0answers
32 views

Security implications of providing an encryption/decryption oracle

I need to provide a service that acts as a symetric encryption/decryption blackbox : the box get a secret key k users send datas d, and get ciphertext c = Encrypt(d,k) users send ciphertext c, and ...
2
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1answer
57 views

Aes encryption algorithm life time [closed]

How many years from now will we stop using aes encryption algorithm, as of now aes seems to be virtually immune to brute force attacks and not showing any weaknesses, will quantum or optical computing ...
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2answers
47 views

AES algorithm encryption time

What is the time taken by an AES Encryption algorithm, with a key of 128 bits, operating on a normal computer (say with Intel i7) and what will be the impact be on the time if I wish to use a 256 bit ...
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1answer
96 views

Is it secure to not expire keys in symmetric encryption?

Note that this question describe hypothetical case, that is never meant to be used in real world. Server communicates with clients with message structure: client_id, initialization_vector, encrypted ...
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1answer
45 views

Which one will give me the best VPN security when choosing Encryption algorithm in pfsense?

I want to setup an VPN server in pfsense and I can choose a lot of Encryption algorithm types ,alot!! What I have read is that the AES 256 (512 is not an option) is the best. Well even then there are ...
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1answer
37 views

Detect if AES and hmac keys are invalid

I have a server which has a configured value of AES and HMAC key. The client also should have the same keys. When the client sends a request, the server interprets this request and reads the message. ...
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0answers
48 views

How can I use session salt for encrypting data using AES in CTR mode?

I have to implement a crypto-plugin in Java. The approach followed is conceptually similar to that used for SRTP. The algorithm used for data confidentiality is AES in CTR mode (I'm following a ...
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3answers
497 views

Encrypting using AES-256, can I use 256 bits IV?

I want to encrypt data using AES in java, and I want to intialize the cipher with Initialisation Vector. Can I use 256-bits IV ? Or I must use only 128-bits IV ?
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1answer
27 views

Does endianness affect encryption keys and initialization vectors?

When encrypting (specifically when using AES) content, will endianness affect how the key (and/or initialization vector) should look when encrypting/decrypting content? And could this depend on the ...
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1answer
45 views

AES subkey generation operations order

I am preparing for my Information Security state exam. There is a question in preparation sheet that asks about order of operations to generate subkey for AES algorithm. Operations listed: XOR with ...
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1answer
35 views

How can the parallelization in CTR mode be attained?

I am using CTR mode to encrypt/decrypt files. Theoretically CTR mode is faster than CFB or CBC because of its individual operations on blocks. In my case CTR mode takes almost as long as CFB. How can ...
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1answer
46 views

How to protect data at rest in a php application?

I was wondering which is the best way to secure data at rest (encrypt / decrypt) in a php application ( eq: stored in a database ) using AES ? Where is the best way to store the keys ?
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1answer
96 views

What is encryption by RSA with AES? [duplicate]

By visiting some websites, like bank websites, we can see for example: TLS_DHE_RSA_WITH_AES_128_CBS_SHA, 128 bits, TLS 1.0 I would like to know: What does mean CBC? TLS 1.0 is an old version, is ...
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2answers
84 views

Would AES encryption of a small number of blocks be less secure than encrypting a large, fixed-size padded buffer?

My application encrypts a file with AES, and the data is read, encrypted and written with a buffer. It's size is defined with a BUF_SIZE value, which is constant. I will try to explain my question ...
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1answer
95 views

Does AES 256 encryption support a master key and generated (time-bombed) keys?

I have a scenario where semi-sensitive [1] data for a corporate web application is to be stored in the browser's localized storage (Indexed DB to be specific, via JavaScript). The intention is to ...
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3answers
156 views

Secure Hash of a very short payload - is it possible?

I am looking to verify the integrity of a very small payload, approx 64 bytes, which will be stored in a QR code. I need to verify that the payload has not been generated or altered by an attacker. ...
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2answers
66 views

Consequences of putting a serial number into an AES key

I have an embedded device with a secure memory of only 128 bits. I have to store the serial number (16 bits) and the AES key (128 bits) into this space. What are the consequences of putting the 16 ...
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3answers
198 views

If TLS 1.2 is considered unbreakable, why do the NSA and other agencies invest in supercomputers? [closed]

If a 2048-bit RSA key and a 256-bit AES key are considered to be unbreakable within the foreseeable future by any kind of computer, why do the NSA and other intelligence agencies invest in ...
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2answers
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Encrypting user credentials using AES: how to hide the key

One of my software (an R package) has to save on disk users sensitive information. I encrypt such information using AES encryption using a random key that is generated at the moment of installation ...
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0answers
128 views

How does Silverlight protect the AES keys it gets from PlayReady? [closed]

I'm doing some research about how Silverlight protects AES keys. Here is the scenario: There is a smooth stream live encrypted channel service. When i log in to the service and tune the channel, ...
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3answers
564 views

Is AES 256 secure enough for putting Backups to AWS or Dropbox?

How long would it take with current hardware to hack an Disk Image which was encrypted with AES 256? I ask because i want to backup personal files (contracts, tax-things, code, keys, private ...
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1answer
50 views

What is the “segment size” when using Cipher FeedBack (CFB) chaining mode?

When using CFB chaining mode with AES, I see instructions that the "plaintext length (in bytes) must be a multiple of segment_size/8" (also mentioned here). What does that mean?
2
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1answer
106 views

OpenSSL implemented AES not according to NIST?

I have been using the Encryption/Decryption code from https://wiki.openssl.org/index.php/EVP_Symmetric_Encryption_and_Decryption. The NIST test vectors (http://csrc.nist.gov/groups/STM/cavp/) for AES ...
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74 views

Hiding symmetric key inside encrypted data

My server generates an AES encrypted file which when downloaded acts as an input for an application. So, should I hardcode the symmetric key inside the application or should I randomly generate the ...
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1answer
124 views

VeraCrypt secure in public?

I have made a Veracrypt Containment that uses AES to encrypt everything inside. But my question is: can I securely put the containment file in public (everybody can access it) without anybody able to ...
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1answer
116 views

AES or Serpent-Twofish-AES [closed]

I want to encrypt my private stuff like credit cards, money, RSA private keys (and so on) but I don't know if I should use AES-256 only or in combo like Serpent-Twofish-AES (I am using Veracrypt). ...
6
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1answer
77 views

Is there any reason to use AesManaged over DPAPI in this scenario?

I have a situation where my web application is going to be deployed on multiple web servers, and I'll be wanting to store some securely encrypted data on the DB servers (each web server has a DB ...
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1answer
55 views

How Secure is my Application?

I have created a little application in .NET that serves as a loader for my other applications. Essentially, when opened, this app will get a list of available applications, and when an option is ...
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25 views

Are there “standard” formats for storing GCM output?

The openssl enc -aes-256-gcm command is broken, because it can't decrypt its own output, otherwise I would look to that as a format. In order to decrypt a file, code needs to be able to separate the ...
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3answers
196 views

Is it possible to wrap and export RSA private key in FIPS 140-2 Level 3 compliant hardware?

I would like to do the following on FIPS 140-3 Level 3 certified cryptographic token using PKCS#11: Generate RSA key pair on token Import AES key from multiple components Wrap and export RSA private ...
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1answer
60 views

Encyption Key Storage and floating point encryption

I am working on a web application where I need to encrypt some fields based on user configuration and display the decrypted information. The field values can be text or integers or floats. We are ...
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1answer
75 views

Simple open-source file encryption tool

I want to securely encrypt files, with an open algorithm. So, i've constructed the simple openSSL shell command. How secure is it? function aes-enc() { openssl enc -aes-256-cbc -e -in $1 -out ...
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1answer
212 views

rainbow table for AES 256 CBC knowing IV, cipher text and plain text

I'm in a situation where I know that I have to decrypt a file encrypted using AES 256 CBC and I've the following details: I know the first 16 bytes block in plain text I know the IV (static 128 bit ...
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How is Tresorit client-side encryption key stored and managed?

I am using Tresorit on Mac OS X and iPhone. When I am using it there is always applied client-side encryption before posting the file to cloud. The key used for encryption is AES-256 and CFB mode of ...
2
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1answer
814 views

Creating a private key with OpenSSL and encrypting it with AES GCM

My goal was to create a private key and to encrypt it with a strong cipher. That key would be used as a root certificate for an internal Certification Authority. However, eventhough openssl supports ...