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.

learn more… | top users | synonyms

1
vote
1answer
101 views

what is the best way to know if the entered decryption key is correct?

I was searching for a way to store the encryption key of AES_ENCRYPT and found a good answer here: where to store a key for encryption However, now I am trying to use "Type in the encryption key when ...
1
vote
1answer
46 views

Can SSL using Blowfish cipher be considered strong enough?

I use OpenVPN to connect to a public VPN. Sometimes I connect from my college campus (it's fully open to alumni) and when this happens I can only use TCP SSL because the college network has a security ...
2
votes
2answers
168 views

Is my sending of encrypted information secure?

Please bear with me as I am not an expert in security. I have a server and a client. On the server I am encrypting a very secret message (using AES256-GCM to hide the information and protect it's ...
0
votes
0answers
31 views

Creating iv parameter in AES encryption

The algorithm that I thought for creating aes key and iv is: Get two values from a certain elliptic curve point that agreed before by using asymetric encryption.(x,y) Aes.Key <- HASH(x) ...
3
votes
1answer
97 views

How can I mitigate against chosen plaintext attacks for AES ECB?

I am developing on a platform where my only encryption option uses AES ECB. The encryption is used to protect parameters that the user can set, and so it susceptible to a chosen plaintext attack. ...
0
votes
1answer
68 views

Which ciphers produce random cipher text?

I already know AES produces a "random" output. 5e4e6440826d6afc4535fbf078455f791159701a9df624ddd4e4dda84523b6a7 Its cipher-text doesn't follow a pattern and is indistinguishable from noise. Is ...
3
votes
2answers
92 views

How can I create a secure random key for AES?

I need to generate a lot of shared keys for an AES method which uses in various condition, my concern is how can I generate unpredictable keys? I've had some research on Cryptographically secure ...
5
votes
1answer
77 views

Why is the Key Derivation Function important?

Let's consider this openssl command : openssl enc -aes-256-cbc -pass pass:PASSWORD Why is it important to have a good Key Derivation Function? This answer to another question suggest that GnuPG is ...
0
votes
1answer
38 views

In NTFS EFS how is the symmetric key (FEK) generated?

I have some old backups that are encrypted using windows EFS and I no longer have access to the certificate used to encrypt the FEK symmetric key included in the files but I do have the password, user ...
1
vote
1answer
56 views

How does AES-GCM handle large blocks with a 128 bit key?

I would like to apply AES-128 byte encryption on GCM mode. I know the logic to apply AES_GCM using 128 bit data. But I have a larger data to encrypt (Not necessarily multiple of 16 bytes). As the ...
1
vote
1answer
55 views

AES in CTR mode. Does both parties have to know the nonce?

I'm a little bit confused. I'm using AES in CTR mode. Do i need an mechanism to send the nonce with the cypertext? Or expressed differently: does every participant has to know the current nonce to ...
-2
votes
2answers
173 views

How are people still copying and redistributing DRM-protected music

...when DRM-protected material is encrypted using the AES cipher, which there are currently no efficiently computable cracks for?
0
votes
1answer
57 views

TOR and Orbot, possibility to add in dynamic AES encryption structure before data is send out? [duplicate]

I read on the documentation about the security issues on TOR, that it is ok if the website is running on HTTPS, but how about on Orbot and site that is not running on HTTPS? Even if it is running on ...
1
vote
0answers
40 views

AES keyfile size

I would like to encrypt files using a key file instead of a password. What I would do is: 1) Generate X random bits using openssl rand X > mykey 2) openssl enc -aes-256-cbc -in secretfile -out ...
4
votes
2answers
172 views

Saving Personal Information (Name, Address, Phone, Email) in MySQL Database

I'm going to build a web app for people to sign up and pay for a membership. The transaction information will all be processed through Authorize.NET but we save the rest of the information (Name, ...
6
votes
1answer
77 views

Using AES with same salt / IV - required for pattern matching algorithm

I need to securely encrypt data we are storing, but for each client I need the same plaintext to encrypt into the same cypher text. The reason for this is the data is still required for a pattern ...
4
votes
0answers
890 views

Why does Java allow AES-256 bit encryption on systems without JCE unlimited strength policies if using PBE?

It's fairly standard knowledge that due to the cryptography export controls, Oracle JRE ships with "limited" cryptographic strength enabled as listed in the JCA Documentation. For AES, the default max ...
4
votes
1answer
130 views

Has there been a breach of AES?

Are there any known logical flaws of AES Cryptography? I understand that you can always break the encryption by brute-force or by having backdoors, but I have not come across any sources that show a ...
4
votes
1answer
46 views

Is there a security risk using a Symmetric-key for both encryption and HMACing

I am proposing to use an AES key to encrypt some data to send to a third party and in a completely separate operation/flow use the same key to create a HMAC of a message to send to the same third ...
8
votes
2answers
211 views

Has anyone validated if KeePass is safe to use? Does it have any backdoors?

Everyone says "the code is open source, go check it out". The truth is, I neither know how to validate the complex code nor can I understand the binaries in code or predict their behaviours. Has ...
1
vote
2answers
169 views

Encrypting unique fields in a Database

I'm still a beginner to cryptography and want to know what the best practice is for solving the following problem: I'm creating an application with the requirement that a user's email address must be ...
0
votes
3answers
108 views

Is it OK to reuse the same SALT key across multiple deployments?

We are building a base application that needs to encrypt SSN, DOB, etc... The application is deployed to many customers. Is it "OK" to use the same SALT key for the AES encryption/decryption ?
5
votes
2answers
282 views

JSON data decryption

Context I am trying to learn more about web security through looking into how various iOS native apps work under the hood. I have been using Burp Suite as the MITM tool to sniff out the network ...
1
vote
0answers
77 views

OpenSSL is not giving correct result for encryption and decryption for FIPS test vector for AES -CFB1

I am running FIPS test vectors against AES-CFB. I am getting correct results for aes-cfb128 and aes-cfb8 but getting wrong results for aes-cfb1. The values being used by me for aes-cfb1 tests are: ...
3
votes
1answer
68 views

What CryptoPP APIs Output Round By Round Results for AES Encryption/Decryption?

I created a program using CryptoPP APIs to implement AES ECB mode with a 128 bit key for encryption/decryption of user input plaintext. I know that ECB is the least secure AES mode but it is ...
2
votes
3answers
63 views

Stacking Encryptions (Stream over Block)

I am reviewing the code for a product our team developed where credit card information is stored in a local database in the event of no internet connection and came across the encryption methods. The ...
0
votes
1answer
43 views

Can I modify a ciphertext created in AES with OFB mode?

Suppose a service uses AES to encrypt Cookies, of the form user=username+padding,tmstmp=timestamp where tmstmp is the expiration time and +padding is a series of zeroes to make the total length be ...
0
votes
0answers
22 views

Security implications of an “obsolete” cipher as indicated by Chrome [duplicate]

I guess this has been asked before, but what are the security implications of the below message? I've seen ciphers such as AES_128_GCM being labeled as "modern". Is this mitigated server side (load ...
1
vote
1answer
88 views

why don't we measure the strength of crypto against the cost it would take to crack it? [closed]

I hear all the time how many hours it would take to break a certain type of encryption. I think this may be the wrong metric to look at ever since scaling became an easy to implement solution. Sure ...
0
votes
1answer
111 views

Why does initial encryption take so long? [closed]

I am encrypting my new 1 TB drive using VeraCrypt and AES encryption. It estimates 9+ hours just for the outer volume to be encrypted. I assume the inner volume will take just as long. Why does this ...
2
votes
1answer
97 views

Security risks of symmetric encryption with compression for database data

I would like to compress data before encrypting and storing it in a MySQL database to reduce especially bandwith requirements. In the future, the DB may be accessible via a web interface. Various ...
60
votes
2answers
8k views

Why has the NSA had a hand in deciding on encryption standards?

The NSA has had a large hand in the design of at least two significant encryption standards: the Digital Encryption Standard, and its successor, the Advanced Encryption Standard. Because of their ...
-2
votes
1answer
367 views

how does AES encryption's algorithm actually work?

can anyone actually explain in simple and plain terms, how does AES encryption algorithm works? i can guess that the only significant distinction between AES-128 and AES-256 is their key size and NOT ...
1
vote
1answer
273 views

is it true that AES-128 and AES-256 are Quantum resistant?

is it true that with the rise of quantum computers, which is pretty close these days, AES 128 and 256 are resistant? while PGP and RSA are not?
1
vote
1answer
117 views

AES_GCM and TLS sequence number

Am I right about that AEAD encryption/decryption uses a TLS sequence number twice, first time in the nonce and a second in additional data? And why did they make the TLS 1.2 sequence number 2 times ...
3
votes
1answer
130 views

Is rounds in a cryptography algorithm same as iterating the algorithm?

In a cryptography algorithm such as AES or DES, does the number of rounds mean same as iterating the algorithm? Example: c= "plaintext"; for(int i=0;i<5; i++) { c = AES(c , "key"); } Where c ...
2
votes
0answers
79 views

Store encrypted data and encryption key on different MongoDB servers? [closed]

In my Rails app users are submitting sensitive username/password combinations to their webshop systems so my app can interact with them. I need to enforce a high data-at-rest security for these data. ...
3
votes
1answer
249 views

Is ccrypt 'AES 256' file encryption fundamentally flawed

The unix/linux utility ccrypt claims to be a more secure replacement for the old unix cryypt. However it seems to me that it has a fundamental flaw. When you encrypt a file using ccrypt it uses the ...
6
votes
1answer
223 views

AES-ECB chosen plaintext attack with long secret

I'm having some trouble understanding the methodology for a crypto exercise I'm doing. The goal of the exercise is to recover an encrypted secret string through a chosen key attack on AES in ECB mode. ...
2
votes
2answers
129 views

Best hash for indexing and searching encrypted data

I would like to be able to do database look-ups on a set of data based on one of the encrypted fields. My understanding of the best practice for accomplishing this is to store a hash of the data I ...
4
votes
2answers
241 views

Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm

I had asked last year about the encryption claims by the web service called https://unseen.is. The very same service that had claims of "beyond army level encryption", "4096 bit keys" etc. This is the ...
1
vote
1answer
43 views

Hashing Based Encryption

Let's say you take a 256 bit key and never use it to encrypt anything. You receive a message with a 16 character unique randomly generated salt pre-pended. You salt your key with the 16 character ...
3
votes
1answer
187 views

IV Reverse AES-256-CBC PKCS#7

I'm a freshmen in cryptography and want to know more about IV reversing. There's a lot of posts about finding the passphrase with a new IV. But what about the other situation? This is for educational ...
0
votes
0answers
65 views

best operation mode for Rijndael-256 in PHP

so my question is about the operation mode. In another thread I heard that ECB is bad which makes sense when I read about it, so I wanna change some things at my Crypto to make it better and wanted to ...
2
votes
1answer
232 views

AES encryption between Java and Ruby: what is the default mode and padding for AES in Java?

I'm writing a ruby app that needs to create some encryption that our java app needs to be able to decrypt. For this I have done some research, and I have this Java code now: Cipher cipher = ...
18
votes
3answers
5k views

How secure is 7z encryption?

I have a text file in which I store all my bank details. I compress and encrypt it with 7-Zip using the following parameters: Compression parameters: Archive format: 7z Compression level: ...
0
votes
2answers
141 views

Standard AES vs additional parameters with Rijndael - what is more secure?

I know that Rijndael and AES are pretty similar and AES is just a subset of Rijndael, and I have read that Rijndael can have 256 bit blocks while AES has "only" 128 bit blocks. The problem is that I ...
5
votes
1answer
2k views

What difference between AES_128_GCM and AES_128 and AES_128_CBC ciphers?

I encountered AES_128_GCM cipher, tried to find it in specifications of TLS1.2 and nothing, any mention. Could some one explain the difference between AES_128, documented AES_128_CBC and this new kid ...
2
votes
1answer
130 views

MasterSecret expansion into keys

I'm trying to deeply understand the steps during a TLS handshake. I've read this answer (which is btw pretty complete), but I stil got a question about the utilisation of the MasterSecret, in the ...
0
votes
1answer
104 views

Is it safe to use the SHA1 checksum of a password as a key for SHA-1?

I have an authentication system, where the passwords are stored with bcrypt hash (node passport module). My server generates a random key (128bytes) at startup. Whenever a user logs in, the server ...