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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1answer
51 views
Different AES 256 algorithms produce different results?
I've tried 3 AES 256-bit CBC encryption programs, and I seem to be getting different results for each one with the same 32-character password, which consists of all @ signs.
They are:
Polaris SSL ...
4
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2answers
51 views
question on hashing an aes-encrypted file
I am storing multiple sensitive data on a server that I do not own. The data is encrypted using aes-256 using cbc mode. The keys are only with me, and are stored securely. I am worried about the data ...
0
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0answers
23 views
Using IV buffer after altered inside a RijndaelCBC Encryption/Decryption process as IV for next message [closed]
When sending a block to be decrypted or encrypted, with RijndaelCBC, we input the data to decrypt/encrypt and an IV for syncing and to prevent identical outputs for identical inputs.
Inside the ...
0
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2answers
39 views
How is the key obtained when I login via VPN?
So, I configure my VPN (let say which uses PPTP protocol), enter the server name, username and password. Then, I visit a website. Before that, my request is encrypted using AES with some key. That ...
3
votes
4answers
259 views
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.
4
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2answers
327 views
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 ...
2
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2answers
78 views
Is splitting up an AES Key a problem?
I'm wondering if it would be a problem to split up a 256 bit AES-Key into two 16-Byte blocks and distribute it, to implement some kind of a four-eyes-principle (you need to persons to decrypt a ...
4
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2answers
148 views
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 ...
5
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1answer
92 views
When do I use NIST AES key wrapping?
Key Wrap constructions are a class of symmetric encryption algorithms designed to encapsulate (encrypt) cryptographic key material. The Key Wrap algorithms are intended for applications such as (a) ...
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1answer
73 views
How to encrypt by AES-Twofish-Serpent
I was wondering how to encrypt by doing a AES-Twofish-Serpent encryption. Does this mean I encrypt in AES first then after that in Twofish, and after that in Serpent (three separate encryptions). ...
0
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2answers
175 views
Can AES-256 encrypted data be changed?
I have a file that supposedly contains AES-256 encrypted data. The file was created using a proprietary program that claims to use AES-256.
I have tested decrypting the file with an open source ...
4
votes
1answer
129 views
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 not masking and padding but we haven't used the ...
0
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3answers
74 views
Ways to keep AES encryption key safe.? [closed]
I am using AES encryption to secure some sensitive data. For that i have to provide a certain key for encrypting and decrypting.
It's not safe to keep the key somewhere on the server. So instead of ...
2
votes
1answer
48 views
Does padding an AES key hurt security (besides lowering the strength of the key)? [closed]
I've been reading about solitare and its weaknesses, and thinking about clever ways of hiding keys. It seems like you could encode an 52-bit AES key in the vertical orientation of cards in a deck (or ...
7
votes
3answers
305 views
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 ...
4
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5answers
202 views
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 ...
1
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0answers
57 views
Using Apple NSKeyedArchiver class without encryption to save score data locally
first of all I'm sorry for my bad English!
I have a question about the security of NSKeyedArchiver, a subclass of NSCoder of Apple Foundation.framework ...
5
votes
2answers
75 views
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 ...
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1answer
93 views
Encrypton method that would encrypt alphanumeric data to alphanumeric data [closed]
I need efficient way(possibly as strong as AES or AES itself) to enrypt (only) aplhanumeric data and get out only alphanumeric data, using some known library (i don't want and intend to implement AES ...
2
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3answers
251 views
Javascript Diffie-Hellman and AES protocols
I am using the BigInteger Javascript library to create a symmetric key using Diffie-Hellman protocol. I want to create 128,160 or 192-bit keys. After some research, I have found out that I should use ...
1
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3answers
168 views
SSL vs Encryption
I am working on creating an android mobile application which needs to connect to a server from time to time. The application makes use of sensitive data which I would not like to get into the wrong ...
2
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2answers
387 views
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);
...
30
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1answer
1k views
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)
3
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2answers
296 views
Key size difference between AES and RSA
Can I say that 128 bit using AES provide more security than 1024 using RSA?
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1answer
190 views
Why can't a AES256-encrypted file be decrypted on machine other than the one it was encrypted? [closed]
I encrypted a file on my mac using openssl
openssl aes-256-cbc -a -salt -in one.jpg -out two.jpg
now if I try to decrypt it like that:
openssl aes-256-cbc -a -d -salt -in two.jpg -out one.jpg
on ...
0
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2answers
118 views
How to implement shamir's secret sharing algorithm using AES_ENCYRPT
I am using MySQL AES_ENCRYTP() and AES_DECRYPT() to store sensitive details in a database, and currently storing the key in a php file outside of the web root with read access only. The key file looks ...
2
votes
2answers
174 views
Login system using authenticated encryption without storing user password
I'm not a security expert, so I might be asking a silly question, but let me describe what I am thinking about.
First, I know that a lot of web sites store hashed/encrypted passwords which could be ...
2
votes
1answer
63 views
Is it safe to derive an IV partially from the secret data if it is hashed before use?
To help ensure uniqueness of IV's used in a CFB AES-256 cipher, software I know of gathers bits from various sources including the plaintext being enciphered, and runs that through an SHA-256 hash. ...
0
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1answer
96 views
Should I run my password through Bcrypt before using it for encrypting a file with AES-256? [duplicate]
I need to encrypt a file with a password that can be memorized. So I was thinking about running the password through some rounds of Bcrypt before using it for AES encryption, so every time I want to ...
2
votes
2answers
120 views
What's wrong with using AES directly/“raw”?
When developing applications that require crypto routines, I know to use libraries like keyczar and libsodium rather than "raw" crypto routines myself.
However, for the specific case of using AES-CBC ...
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1answer
120 views
Which is more secure, AES or Rijndael? [closed]
Which algorithm is generally considered to be more secure, and is AES-192/AES-256 still considered to be secure?
After reading this it's lead me to belive that the Rijndael algorithm would be a more ...
2
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1answer
158 views
AES in CTR mode with same random IV to create same ciphertext
I am currently working on a little project.
I am trying to generate an AES key with that I would like to encrypt a private RSA key. I have to do it this way. However, I do not want to save the AES ...
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1answer
255 views
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 ...
0
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1answer
223 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 ...
5
votes
2answers
311 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 ...
4
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1answer
606 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 ...
3
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1answer
201 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 ...
1
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1answer
164 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 ...
6
votes
6answers
327 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 ...
2
votes
4answers
926 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 ...
1
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2answers
413 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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1answer
98 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 ...
2
votes
2answers
253 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. ...
0
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2answers
363 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 ...
0
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1answer
489 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).
...
5
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2answers
262 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 ...
0
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1answer
943 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 ...
3
votes
2answers
312 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 ...
3
votes
1answer
227 views
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 ...
3
votes
4answers
234 views
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 ...
