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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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 ...
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54 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 ...
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156 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?
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52 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 ...
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39 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 ...
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154 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, ...
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1answer
70 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 ...
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695 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 ...
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1answer
129 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 ...
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1answer
45 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 ...
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2answers
195 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 ...
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159 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 ...
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3answers
103 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 ?
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252 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 ...
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0answers
76 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: ...
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65 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 ...
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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 ...
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1answer
42 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 ...
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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 ...
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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 ...
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1answer
101 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
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1answer
87 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 ...
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7k 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 ...
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226 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 ...
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245 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?
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1answer
101 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 ...
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127 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 ...
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76 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. ...
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1answer
224 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 ...
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1answer
208 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
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2answers
122 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
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2answers
237 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 ...
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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 ...
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179 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 ...
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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
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1answer
219 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 = ...
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3answers
4k 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: ...
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2answers
129 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 ...
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1answer
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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 ...
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1answer
126 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 ...
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1answer
102 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 ...
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1answer
150 views

How to wipe disks before encryption with dm-crypt if CBC or XTS is used internally?

First, please forgive me if I'm posting this question to the wrong community. Feel free to migrate this post to the right community if I was wrong. I'm quite new to whole disk encryption (but not ...
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2answers
92 views

Can EAP-TLS and AES256 encryption be used together?

What is the difference between EAP-TLS and AES 256 encryption? Can they be used together? Or are they separate protocols?
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302 views

How to unwrap exported key from safenet HSM? [closed]

I am trying to write a software that will inject keys generated inside an HSM into a POS device, in the same way as described here I'm using the Safenet emulator(software-mode) + the wrap/unwrap ...
0
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1answer
139 views

How can I secure encryption keys in the code? [duplicate]

I have files on the server that is encrypted with AES. I am developing iOS and Android apps to decrypt and process those files in the phone or tablet. To decrypt files on the client apps, I have to ...
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1answer
70 views

Should I worry about padding oracle?

I have a PHP webapp which encrypts (by AES192-CBC) messages with a random key and a random IV. Everywhere people are saying how amazing are GCM, EAX and authenticated modes (does currently exist safe ...
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177 views

Securely store session data in cookies

I'm trying to create a stateless application server architecture and I would like to store session data in cookies. All pages using the session would be served over HTTPS. I was planning on using ...
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3answers
172 views

What benefit to use different encryption key (passphrase) for different customers?

When we store confidential information in our database, we encrypt it using AES. In addition, when customers install our product, they protect their machines using a firewall. Should we use different ...
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236 views

Am I encrypting and storing an array of user-details correctly?

I came up with a user-details-storing procedure that was, in the beginning, based on actual security-literature – but then I just kept writing without really doing all the cross-checking I should have ...
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2answers
478 views

Practical steps for encrypting an encryption key for data stored in MySQL

So I'm working on my first project where user data is stored as encrypted using the user's password as (part of) the key. I have read many similar things about best practices, but the details seems to ...