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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Cascading Encryption Algorithm using mcrypt or GnuGP
I'm trying to a cascading cipher encryption algorithm to encrypt a textfile via mcrypt. I'm essentially trying to emulate the behavior of TrueCrypt, where it can cascade two or three different cipher ...
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89 views
Using JTR to crack Skype Passwords
The scenario: coworker's Skype somehow lost his auto-fill password. He doesn't remember it anymore, and the account is hooked up to an email address that no longer exists. He's never purchased any ...
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130 views
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 ...
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75 views
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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196 views
Remote System Administration of an Encryption-Switch-Encrypted Infrastructure
I can't seem to find a decent explanation anywhere of the practicalities of remote system administration (e.g. SSH) of an encryption-switch-encrypted SAN-stored infrastructure.
The environment will ...
5
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334 views
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 ...
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1answer
71 views
Is OpenSSL AES GCM standardized?
I have been reading about the perils of not going the pages of my own encrypt-then-mac implementation, because there so many things can go awry. So decided to use EVP_aes_256_gcm.
But some questions ...
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273 views
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 ...
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2answers
207 views
Questions to hybrid encryption. RSA with AES
I want to use a hybrid encryption in my application, so after reading a lot of lines I ended with this implemantation, please critizie it ;) (I want to stick to .Net)
byte[] aesKey = ...
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4answers
284 views
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 ...
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68 views
What mode of operation is secure for block ciphers?
as RC4 is not secure and AES-CBC is same thing the only solution is using EAX mode for AES. but why mozilla NSS don't support EAX mod ? is there any secure EAX implementation ? and why wikipedia says ...
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176 views
7zip AES encrypted archive, padding oracle attack
I created an encrypted but forgot the password. When I attempted a pattern based brute force it said it had over a 100 trillion passwords to check. And to my knowledge that could take a few years. ...
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2answers
413 views
How long would it take a single Processor with the AES-NI Instruction Set to bruteforce an AES Key?
I know that it seems like a stupid question - since it's note feasable to break AES without a quantum computer but I'm curious anyway.
I read on wikipedia that the best known attack on AES-128 takes ...
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2answers
181 views
Where do I securely store application-specific symmetric key?
I am writing an application App1. This application uses SQLite database and I plan to encrypt it using AES256. For symmetric encryption I need a key, which I need to store somewhere.
From a similar ...
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Is it possible that AES could be broken? [closed]
Much like DES was broken for years, but never truly released to the public until quite some time later. I know that AES was more open to the public when it was initially developed, and many proposed ...
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Wheres the salt on the openssl aes encryption?
Im 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 them
...
3
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2answers
189 views
LastPass One Time Recovery Passwords--How?
The LastPass password manager stores One Time Recovery Passwords locally in each browser you use the plugin with:
http://helpdesk.lastpass.com/account-recovery/
My question is, how can you have more ...
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1answer
101 views
Implementation review - Independent key, admin side and user side
The admin of the website needs to read user data. So, if the key is derived from the user pass, then the admin has to know the user pass, not exactly a good idea.
The following encryption scheme was ...
3
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125 views
Confidentiality and integrity for web session
When the client authenticates with our service, he is issued an opaque "token". This token includes the information, that identifies the client and some other information about the client ("payload"). ...
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242 views
Can active attacks really decrypt a particular AES-256, CBC, PKCS#7 encrypted file?
I recently found out that active attacks are a threat against AES-256, CBC mode, padded with PKCS#7 (the CBC mode in particular. I should supposedly change to EAX to guard against these attacks).
...
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2answers
218 views
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 ...
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375 views
How does PKCS#7 padding work with AES-256, CBC mode?
I'm a bit confused with AES-256, CBC, and how it works with padding (PKCS#7).
Whenever I encrypt data of multiples of 16 bytes (the block size), extra 16 bytes are always padded at the end.
For ...
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Key length and hash function in PBKDF2
On this page:
http://www.ruby-doc.org/stdlib-2.0/libdoc/openssl/rdoc/OpenSSL/PKCS5.html
they make a statement that strikes me as rather weird:
Key Length
Specifies the length in bytes of ...
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Is it safe to have the salt equal to IV?
If I'm using AES-256 CBC to encrypt, getting the 32 byte key using multiple iterations of the PBKDF2 function with a 16 byte salt, is it safe for me to let IV be equal to the salt?
(Edit: The salt is ...
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Key distribution advice
I have been thinking for days about that problem! The application is based on a student system management. I am implementing database encryption on a column level and The encryption occurs at the ...
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347 views
How X509 Certificates are used for Encryption
I have small doubt regarding the process of X509.
I am aware of OpenPGP Encryption/Decryption, where we generate the public key and private key. We can share the public key to vendors and they can ...
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1answer
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What AES mode does SQL Server 2012 use?
I looked at this link that shows how to encrypt a SQL column via a certificate (RSA??) and AES256.
I created a dummy table (script at GitHub) intentionally using identical plain text (Credit Card = ...
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1answer
134 views
AES encrypt secret key with plaintext
We need to be able to retrieve password. Hashing is one-way, we can't do that.
So we ended up using AES.
We want to know if the following schema is safe or not. I am only familiar with modulo PK ...
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2answers
496 views
Why does OpenSSL not include AES-256-GCM? [closed]
I'm trying to implement AES-256-GCM in Ruby.
Ruby's OpenSSL wrapper library and aead library both clearly seem to believe that OpenSSL itself supports this.
However, neither 0.9.8r (which I had ...
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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 ...
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2answers
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Slow down symetric encryption
I'm developing a program in Java. In one step data should be encrypted and exported in a file.
As of now we are encrypting in AES-256
I want to slow down a possible brute force attack as much as ...
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Weakness of AES OFB mode
I found these comments regarding AES OFB Mode "This mode is a slightly less common mode, quite similar to CFB above, but which should not be used as a stream cipher due to inherent weaknesses when the ...
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Securing the SOAP Messages
One of my clients wants to encrypt few sensitive information which will be transferred through webservices / SOAP.
My client has the following suggestions:
Encrypt the sensitive data with AES ...
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356 views
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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aes cfb 128 decryption /encryption problem between Erlang and PHP
Update 2 - it works
Thanks to Tom Leek for his answer.
The CFB mode of mycrypt for Rijndael uses a 8-bit feedback loop and not a feedback loop the length of the key/iv.
You have to force it to use ...
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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?
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How to correctly implement AES in a backup application
I am writing a back-up application which should have the feature of encrypting the back-up. It must encrypt file data, paths and filenames. The application is being written in C# (.NET). Target is ...
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Remedy for not having filled the disk with random data?
Filling a large HDD with /dev/urandom prior to encryption can be extremely slow (even with netcat, multiple instances in parallel, etc) and for this reason I'm sure a lot of users skip this advice ...
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Need advice on Cryptography digital files project
I have to choose a topic for my end-of-year school project and I need some advice. I was thinking of implementing an online tutorial materials (digital files) project. I have been researching on ...
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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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1answer
456 views
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 ...
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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. ...
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756 views
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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How does Cipher Block Chaining relate to AES?
I was reading FIPS197 for a class (found here: http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf ) trying to find some sort of specific relation between CBC and AES. I guess my problem is ...
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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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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 ...
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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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Where can I find information about how to implement Intel embedded AES256 encryption?
I heard this can really speed up encryption performance, but I can't find any good information about how to implement it.
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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 ...
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Password protection of encryption and signature keys
I would like to store encrypted backup of text files on my computer. I'm developing a python script using Pycrypto to achieve that, based on this code to use the library. (current code)
The basic ...
