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AES (Advanced Encryption Standard) is a symmetrical block-cipher algorithm with a 128-bit block size, and key sizes of 128, 192 or 256 bits.

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How to Prevent Correlation Power Analysis Attack on AES?

Which techniques could be applied to AES to prevent these kind of attacks? I can just think of creating noise with a parallel process for random computation, so the signals have the combination of ...
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problems decrypting alphanumeric characters to original text [on hold]

I'm using openSSL aes_cbc128 to encrypt/decrypt some text coded in C++. When I run with only numeric data, everything is fine. When I run with alphanumberic data, the last block does not decrypt to ...
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WebCrypto AES-GCM vs AES-KW for key wrapping

The Web Crypto API available in most browsers supports both AES-GCM and AES-KW for key wrapping. There are examples for AES-KW and AES-GCM performing key wrapping, and a popular live table indicates ...
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Variation on the ECB Penguin problem [on hold]

So this is an age-old example of why encrypting images with ECB is a terrible idea, since the underlying pattern of the image remains the same. Referenced from: If you encrypt an image (AES), is it ...
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using a hashed IV for AES128-CBC

I would like to minimize the encrypted packet size. Is it possible to derive the IV from a non-repeatable counter? For example, take a 32 bit counter, hash it with a key (different from the AES key), ...
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3answers
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How to do Hexadecimal multiplication in GF(2^8)

I'm trying to do a hexadecimal multiplication in GF(2^8). Now, I know the technique of shifting left the binary numbers in some cases, for example: 02 * 9E 0000 0010 * 1001 1110 you shift one time ...
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1answer
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Practical quantum attacks on AES - Is AES-128 used in a block mode vulnerable to attack using quantum algorithms

Can Grover's (or similar) algorithm be used to attack AES-128 when used in cipher modes like CTR? It seems like the answer is no... Also I have a similar question for SHA256 when used for a MAC. It ...
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66 views

How we can calculate AES Inverse SBox?

I am trying to find out the inverse of and SBox, but in vain, I have seen multiple questions over StackExchange, But I cant be able to solve my issue. As in this question, How are the AES inverse S-...
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AES blocks with a counter

I would like to send small separate packets of data. I am thinking of using AES-128 or AES-256, and to add a counter as part of the plain text message. Some clarifications: Each message will be one ...
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2answers
132 views

Attacking AES128 with Grover's algorithm

How many plain text / cipher text pairs are required by Grover's algorithm when it is used to try and discover a secret AES key? I am trying to determine if having a device which limits the speed at ...
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1answer
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AES without mode operation

i have field in database. ex: field name. this field maybe more than 16 byte. how to encrypt data more than 16 byte without cbc, etc? any function or another ways to do this?
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What is the shortest type of text encryption?

I have the following text that I want to encrypt with a password: "This is my secret password: 1234567890" encrypted with AES: SgAHzFc3vluxLqZuzZKg8dzhy918N41SUU1BfBXN8CoEDfVJ0R9hox8PT2jKYA== pass:...
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1answer
140 views

Vulnerabilities of AES method that uses MD5 to create the key

Are there security vulnerabilities given the would a user be able to access the original text and the encrypted text with AES using an MD5 as a key? In other words, if the user had both the original ...
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256 AES encryption [duplicate]

I am quite new to cryptography and I've been trying to learn a lot recently and this might be a theoretical question. So I know that 256-bit AES encryption is very hard to decrypt and that a non ...
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1answer
71 views

AES-128 as compression function in Merkle-Damgard construction

Using a compression function $f : A × A → A$. A basic version given by: $W_0 = IV$ $W_1 = f(W_0, m_1)$ $W_2 = f(W_1, m_2)$ ... $W_n = f(W_{n-1}, m_n)$ $W_n$ is the output of the hash function, $...
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1answer
48 views

Does it matter how the IV and XOR are applied for a single AES-128 block?

I want to encrypt 128 bits of data. I understand the problem with ECB, so I generate a 128-bit Initialization Vector to use for encryption and send with the encrypted data. Is there a "best" way to ...
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1answer
31 views

Encrypting/Decrypting sensitive information for storage purpose

I want to store account numbers and routing numbers into SQL database, and i was looking for best way to encrypt/decrypt this sensitive information. After researching i found i can use symmetric (like ...
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1answer
87 views

Decrypting an encrypted aes 256 cbc text with random IV, decrypts the string [duplicate]

This may be a basic question but bear with me. I started encrypting a text with aes 256 cbc mode generating a random iv of 16 bytes and a key. ...
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OpenSSL decrypt AES 256bit (base64) encrypted password - wrong final block length [migrated]

I am trying to decrypt aes-256-cdc encoded password using OpenSSL ...
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2answers
65 views

Inverse MixColumns Operation of AES

I am aware that MixColumns is a mixing operation which operates on the columns of the state, combining the four bytes in each column. So we multiply our state with ...
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1answer
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AES MixColumns Predefined Lookup 2D Tables and Rcon Predefined Lookup 2D Table

I need to have the a copy of predefined 2D table lookup for AES MixColumns when state is multiplied by 2 and 3, 9,11,13,14 and also the Rcon predefine table. I search it everywhere but I couldn't ...
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1answer
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Is AES-CBC mode not secure against chosen cipher-text attacks even if the IV is not predictable?

I've seen questions where people have asked if AES-CBC mode is vulnerable to chosen cipher-text attacks if the IV is predictable. But is it guaranteed to be secure against chosen cipher text attacks ...
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Is it possible to determine the number of characters used for a password used to encrypt a file with AES 128?

I lost a password for an ethereum wallet at the end of 2016. Computer immediately shutdown and password was not recoverable. I know there are many potential avenues for narrowing my search for what ...
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How do we perform second order differential power analysis attack?

I have read papers which describe that the power traces(acquired from a side channel resistant implementation like masking) need to be centered and squared, then a correlation needs to be performed ...
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Is AES easier to crack when the input is small?

Say you just want to encrypt a number. For example, say the number could be any double. A double in C# and Java is 8 bytes. If you were to encrypt a double using ...
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How does IES compare versus AES and RSA? [closed]

How does IES compare versus AES and RSA in terms of speed and security?
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Broadcasting a message with multiple sub-messages encrypted for different recipients

I'm looking for an encryption scheme that can be used in a P2P system were broadcasting of messages is used to propagate these to all participants. A participant would create a single/large message, ...
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3answers
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What's happens if we use the weakest S-BOX for AES?

I'm in research of generating Dynamic Secret S-BOX for AES based on 2 Keys (Encryption Key and *I Called S-BOX key). If (worst scenario) I randomly generate the worst S-BOX in an encryption. What ...
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1answer
120 views

Hash-Then-Encrypt or Encrypt-the-Hash?

My question is would it make any difference if I use SHA3 and hash a block of data and then encrypt it using RSA is most secure to do the reverse? The question is about Site-To-Site transmission ...
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1answer
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AES-128 (cbc mode), is it possible to deduce the IV if the plaintext, ciphertext and key are known?

I have the plain text, key and the ciphertext stored in DB. Can I deduce the IV based on this information?
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1answer
101 views

AES - which cipher is the safest one out there and what are the best practices for creating and storing the key

I just started to learn cryptography. I've read a ton of articles but couldn't find a book or a course that is based on this subject (and also is not outdated). Therefore I have a few questions (...
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Hardware AES: can we have a decryption implementation only?

I'm wondering if implementing only the AES decryption can reduce the hardware cost? And does anybody have some examples of the cost (speed, size) of hardware AES implementation? Thanks, Abaobaide
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In AES-GCM, is it secure to not GHASH the lengths to create a tag?

In AES-GCM, one of the steps includes a GHASH of the length(A) || length(C). Under the condition that that the length of A == 0, ...
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1answer
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Is using derived keys for HKDF + AES-GCM safe

I have an existing system which takes a cryptographically secure BLOB from user and pass it to lower API which calls HKDF-Expand to get 2 keys: one is effectively discarded in this scenario and second ...
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1answer
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AES ECB mode for both encryption and authentication

Can AES ECB mode be used for both encryption and authentication, assuming the following conditions are always true? Encryption of exactly 128-bit (1 block) size messages Different keys used for both ...
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How computationally heavy these algorithms?

I want to use Signal protocol to encrypt sensors data. As we know sensors have limited memory, CPU power, and battery. And Signal protocol has the following processes: Encryption: AES in CBC mode and ...
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1answer
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Does an IV need to be used in AES CTR mode?

If I encrypt a message once using AES CTR, will I need an IV? Additionally, if I do use an IV, will I need to send with with the cipher text?
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Is it ok to transmit an IV as a custom HTTP header?

Considering an AES OFB encryption algorithm, suppose that I'm sending a message over HTTP (not HTTPS) and my message body contains the cyphertext. I'd like to know if transmitting a random ...
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Can I hash a secret key and used the hash as key ID?

I am using AES-CBC to provide confidentiality for protocol messages. I want to allow the receiver to know the secret key by using a key ID. For this I hash the secret key to generate a key ID. Every ...
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1answer
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what is the impact of smaller bit size sbox

There are multiple S-boxes type, as DES uses 4 bit S-box and AES uses 8 bit S-box. I want to know how this effect the security?? If we use 4 bit or 8 bit. apart from the DC attack. Both provides ...
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Help decrypting AES-256-CBC data with bad initialization vector of 0xC0FFEE

For a game I am trying to decrypt data that was originally encrypted using AES-256-CBC given a key and the following initialization vector: 0xC0FFEE The initialization vector appears to be short, ...
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Active S-Box calculation [duplicate]

As stated in AES proposal that minimum number of active S-boxes in any 4-round differential or linear trail is 25. How can I find the number of active s-boxes in AES?
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Calculate all possible keys for AES 128 encryption to exploit hardware encryption

Some background: I am using the MicroChip ATAES132a for hardware encryption/decryption. The ATAES132a is very configurable and can be misconfigured in such a way that the encryption/decryption will be ...
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1answer
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Is it possible to unpad a file that is not padded

I used "AES/CBC/PKCS5Padding" to encrypt some files. But I did not provide any identifier to detect if the file is encrypted or not. Now one way to detect if a file ...
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1answer
106 views

Use AES in CTR mode with pycrypto

The doc of pycrypto gives an example of using AES in CTR mode: ...
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1answer
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What is ANSI X.923 padding standard?

Wikipedia defines ANSI X.923 padding as follows: In ANSI X.923 bytes filled with zeros are padded and the last byte defines the padding boundaries or the number of padded bytes. Example: In ...
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1answer
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How much time does AES decryption take?

I am attempting to decrypt a 90 GB file that is encrypted using AES-256. I have the password. How long should this take to complete? I've had the process running for over 3 days with no progress.
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Reverse cascaded AES encryption

I was wondering if it is possible to decrypt a cipher-text using a single key which was encrypted twice. For example: Let's assume that we encrypt a plaintext using AES-CTR and encrypt the output ...
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1answer
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AES-GCM GHASH calculation;

I'm trying to make an GHASH() function and need some clarification. Implementation is based on gcm-spec. Page 8 describes polynomial mult and page 27 has a "Test Case 2" which I use to verify result. ...
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1answer
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Real time video stream AES encryption with authentication

I am now studying the AES encryption for real-time video stream. It seems that Netflix uses the AES-GCM (or CBC + MAC) mode for real-time video encryption and authentication. With MAC authentication, ...