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 AES encryption take more time than decryption?

While I was studying the time consumed by some methods I found that encryption take more time than decryption. Is this right? I am using AES (the same steps will be taken during the enc and dec)
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Is AES encrypting a password with itself more secure than SHA1?

This isn't really a practical question, but more a question of curiosity. I heard a CS professor recommend stepping up from md5ing passwords not to SHA1, but to AES encrypting the password using ...
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Is it safe to write the salt AND/OR the IV at the beggining of an encrypted file?

I want to encrypt a file with AES in CBC mode (maybe another mode is better for file encryption...I don't know, but suggestions are welcome!). What I usually do is that I first write a few random ...
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Security comparsion of 3DES and AES

Which one is more secure and least possible to be broken through cryptanalysis AES or 3DES (no matter performance)? I need to use encryption for my projects to store and secure sensitive information ...
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Does AES-192 provide better encryption than AES-256?

this wikipedia article describing AES says: Related-key attacks can break AES-192 and AES-256 with complexities 2^176 and 2^99.5, respectively. Does this mean that AES-256 is actually a weaker ...
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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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Where is the salt on the OpenSSL AES encryption?

I'm interested in knowing how and where OpenSSL inserts the generated salt on an AES encrypted data. Why? Im encrypting data in Java classes and need to guarantee that I can use OpenSSL to decrypt ...
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What's the advantage of using PBKDF2 vs SHA256 to generate an AES encryption key from a passphrase?

I'm looking at two comprable pieces of software which need to encrypt data on disk using a passphrase. One uses PBKDF2 to generate the encryption key from a passphrase, while the other uses two rounds ...
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Encryption - should I be using RSA or AES?

My model is one where I have several clients which wish to speak with some (but not all) of the other clients. All messages will be sent through a server. Only the two clients communicating with ...
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How secure is Intel SSD Encryption?

Are there any known flaws in the full disk encryption on Intel 520 series SSD drives? Specifically, it seems these drives generate an internal AES key automatically, even when no password is set. But ...
10
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Is AES-GCM recommended for SSL?

I'm looking at turning on site-wide SSL for a website I manage, and I'm wondering what the best practices for SSL configuration. I'm not too worried about compatibility with old browsers and more ...
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SSL/TLS - Distinction between self-signed cert and self-signed CA, and other questions?

I have a small personal website which I wish to serve securely over HTTPS. At the moment I do not wish to use a third party CA to sign my certs. I was reading this document on generating a self-signed ...
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How can I encrypt a file with .NET and have the same file size of the original file?

I'm using .NET and I've written an awesome routine (xD) that encrypts and decrypts a file using AES256 CBC. It works perfectly, but now they told me that the encrypted file must be of the same size of ...
9
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When using AES and CBC, is it necessary to keep the IV secret?

If I encrypt some data with a randomly generated Key and Initialization Vector, then store all three pieces of information in the same table row; is it necessary to encrypt the IV as well as the Key? ...
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816 views

AES using derived keys / IVs. Does it introduce a weakness?

I'm looking for an efficient way to encrypt multiple fields in a database with AES using a single global key, used throughout a large web application. Obviously in order to re-use this key, a unique ...
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Is “Why Should You Avoid AES In MySQL?” true?

From a 2012 Smashing Magazine article quite a bold statement is made to avoid AES in MySQL itself. Or as they put it "Why Should You Avoid AES In MySQL?". However, if you search for SQL encryption, ...
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Verify Login and Encrypt with PBKDF2

I'm writing a desktop application where I'm using PBKDF2 to generate an encryption key to AES-128 encrypt the config file. The config file contains a crypo-random key that's been used to encrypt the ...
8
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Authenticated Encryption vs. contained and encrypted checksum/hash?

So I read through http://en.wikipedia.org/wiki/Authenticated_encryption and http://www.cryptopp.com/wiki/Authenticated_Encryption and I don't seem to be following the concept. From the simple ...
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How can I securely convert a “string” password to a key used in AES?

I'm writing some software where I have to encrypt all files that are written to a specific folder using AES. There is one password/key that is configured somewhere, that is always used. I don't want ...
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I don't see how “-salt” in the openssl command line tool enhances security at all

I do this to encrypt a single file: openssl aes-256-cbc -a -salt -in file.txt -out file.enc and then type in some regular plaintext password. I do not understand how -salt enhances the security of ...
7
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How to circumvent compromised CPUs in major FOSS operating systems

As Matthew Green puts it, "the NSA has been ... Working with hardware ... vendors to weaken encryption and random number generators." At this stage, however, there is little public knowledge of which ...
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What are the variables of AES?

AES is a standard encryption routine that can be used consistently across multiple languages, assuming all the variables match up. My question is, what are the variables. I am aware of the following ...
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Can someone explain a little better what exactly is accomplished by generation of DH parameters?

I'm setting up a node.js server: https.createServer({ ... ciphers: 'ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH', honorCipherOrder: true }, app).listen(443); ...
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Is leaking the hash of your encryption key a security risk?

I've been trying to design a simple archive format, that allows me to just bundle a bunch of encrypted files together. The idea, I currently have is to embed not the encryption key but a truncated ...
7
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Filling the disk with random data prior to encryption?

Filling the disk with random data prior to encrypting it will supposedly make it harder for the attacker to perform any cryptanalysis. Most sources seem to state this is because it will be harder for ...
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Recommended options for LUKS (cryptsetup)

I'm looking for recommended options for cryptsetup to create fully encrypted SSD (SanDisk SSD U100 128GB), which achive: Timing O_DIRECT disk reads: 1476 MB in 3.00 seconds = 491.81 MB/sec Timing ...
7
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1answer
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What's the hash for in ECDHE-RSA-AES-GCM-SHA?

Presumably the SHA is for deriving the AES key from the shared secret. Where else is the hash used? ECDH just does ECC (no hashing). RSA does masking and padding but this doesn't involve the ...
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Does the endianness used with an encryption algorithm affect its security?

I'm implementing the AES block cipher, which reads/writes data in 16 byte blocks. The implementation I'm working with usually read data in the little endian format. But in my platform the endianness ...
6
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937 views

Should AES always give the same output?

I'm having trouble understanding AES and would like to know if encrypting the same text with the same key two times in a row should give the same output. Is there any salt or something that would ...
6
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3answers
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Is multiple encryption a good idea?

I know that many encryption algorithms, while secure, have vulnerabilities. To reduce risks, would multiple encryption like this Blowfish_CbC ( Rc2_OFB ( AES128_CBC (myfilecontent))) be a good ...
6
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How less secure is an encryption if we know something about the original data?

I have a number of files encrypted with a key derived from a password. In line with standard practice, I use a random salt and password and do many PBKDF2 iterations to obtain an encryption key and ...
6
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Implications of having a service account in AD use RC4 rather than AES for Kerberos?

Bear with me, I know this is sloppy, but here is the back story: We have a partner that uses Jira and is using spnego with a custom auth back-end that expects certain group membership in the token. ...
6
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WPA2 Enterprise AES encryption key size?

I have recently set up a RADIUS server with EAP for my wireless router, however, I have some questions about the key size and how WPA2 enterprise (AES) works in general. I have read that in ...
6
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1answer
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OpenSSL fails NIST AES-128-ECB test vectors?

I'm having trouble getting OpenSSL's ciphertext to match the NIST test vectors. Example : in "ecb_e_m.txt" from http://csrc.nist.gov/archive/aes/rijndael/rijndael-vals.zip, the first test is (in hex) ...
6
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1answer
641 views

Android and AES side channel attacks

I am working on a project that will involve symmetric AES 128 bit encrypted communication between an Android application and a bluetooth device. Are there any public AES libraries available for ...
5
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Is 1Password more secure than an AES encrypted text file?

Are there extra measures taken by 1Password and KeePass, that make them more secure than an AES-256 encrypted text file? The database formats they use seem needlessly complex for my own purposes.
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Designing a cryptographic file-sharing protocol

As a learning project, I am trying to implement a secure way to share files with a friend over dropbox. (I am not looking for existing software, I am doing this in order to learn how to do this ...
5
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4answers
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RSA maximum bytes to encrypt, comparison to AES in terms of security?

What is the maximum number of bytes for encrypting a plaintext message using RSA that is reasonably secure and also efficient and would AES be better for the same size in bytes? The encryption doesn't ...
5
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628 views

How to encrypt more than 16 bytes using AES?

I am trying to implement AES on an image of size 256x256 (65536 bytes) but AES works on 4x4 size of image (16 bytes). What should I do? Can it be implemented or not? And if yes, then how?
5
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Encrypting using AES 256, do I need IV? [duplicate]

I'm looking into encrypting with AES using a 256bit key, and I notice that a number of methods in various languages, for instance http://php.net/manual/en/function.openssl-encrypt.php, and I notice ...
5
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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 ...
5
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4answers
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TrueCrypt -vs- MacOS encrypted sparse image - equally secure? Other alternatives?

I'm currently trying to find my personal best solution for storing passwords and other sensible data. Recently I've used 1Password on iPhone and Mac but I'm not really satisfied with its predefined ...
5
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AES CBC padding when the message length is a multiple of the block size

Assuming that a 32-byte plaintext is encrypted by AES 128 CBC - is it mandatory to add 16-byte padding, according to the different padding schemes?
5
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2answers
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Security sanity check

A company whose services I'm trying to integrate uses this protocol: An AES key is embedded in an Android library. To authenticate itself, the library sends a SHA1 hash of the key over plain HTTP. ...
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After How Much Data Encryption (AES-256) we should change key?

Considering AES-256 encryption, what is the maximum amount of data should be encrypted with one key? Does Block cipher modes/IV/counters also governs the limit? If say the maximum amount is 50GB, ...
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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 ...
5
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Benefit to using PBKDF2 on key generated by RNGCryptoServiceProvider?

I have a program that generates a fixed-length 32 byte (256-bit) password using RNGCryptoService provider and then uses Rfc2898DeriveBytes on that password to arrive at an encryption key. However, to ...
5
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2answers
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Serving data from an encrypted database over an encrypted connection

There is encrypted data in the database (asymmetric FYI). It is to be viewed as decrypted on the website. The data can be sent to the client as encrypted to be decrypted on the client's computer, or ...
5
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1answer
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Security of bcrypt/sha256 key used with AES to encrypt a file

I'm looking to encrypt files using secure hashing and encryption algorithms in Python. Having used bcrypt in the past, I decided to use it for my passphrase calculator, then pass the output through ...
5
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AES256, repeated IVs and mostly-costant payload: how ok/bad is that?

I recently came across an application that more or less does this: starts from a (supposedly unknown to others) key generates a random IV encrypts some smallish (~ 160 bytes) payload with the key ...