Encryption is the process of transforming plaintext using a cipher to make it unreadable to anyone except those possessing the key.

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How do I transfer the HMAC?

I have a file I'd like to encrypt with a symmetric key using AES-256 and then use an HMAC for integrity. So I don't "roll my own" scheme which I know is a big mistake, what are the standards for using ...
2
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1answer
326 views

Can we reverse engineer binlog with row format to make MySQL AES_ENCRYPT visible?

Suppose if I am using the mysql database based encryption using AES_ENCRYPT function & insert records, is it possible to decode the row formatted binlogs generated by MySQL to obtain the actual ...
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2answers
551 views

Is it bad practice to send decryptable data?

If I'm authenticating an action, is it a bad practice to authorize the connection using a decryptable hash that does have a specific algorithm, but only the remote machine knows? Is sending ...
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3answers
806 views

Use Authentication using 2 encrypted strings

So, basically I am trying to log a user in with a cookie and do not query DB to improve performance. Here is a brief idea: Transmit everything via SSL Set a Global secret key A and secret key B ...
3
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2answers
739 views

Encrypting Fields in Database

I'm working on an ASP.NET web application that will have to store sensitive information. I would like to encrypt the sensitive fields to protect against any possible SQL injection vulnerabilities. ...
2
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1answer
548 views

Does SQL Server CE 4 decrypt data securely?

I am going to store data in an encrypted SQL Server CE 4 database, where the database is doing the encryption. (Note that SQL CE is the embedded version, not the fully installed server.) When the ...
4
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2answers
318 views

Evernote hacked - precautions?

On March 2, 2013, the digital note taking system Evernote was hacked. Evernote has forced new passwords and have released new updates to Windows, Windows phone and iOS of their client software. ...
4
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3answers
568 views

Can encryption twice with two keys in different sequences lead to the same result?

I am looking for an encryption algorithm for one of my current papers. The basic requirement is that, suppose I have two keys k1 and k2, and the E(k1,t) means encrypt t with key k1. Are there any ...
10
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1answer
24k views

Why so long to break 128-bit encryption?

I read that 128-bit encryption takes millions of years to break. But if I encrypt a file using say winzip that uses 128-bit encryption but the password I use is only one character long (for example ...
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1answer
2k 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). ...
6
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2answers
590 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 IV....
3
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3answers
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Recovering encrypted SD card after Android Factory Reset

I was using Active Sync on my Android Galaxy S2 and as a result it enforced encryption of the phone and SD card. Phone did a factory resync and now data on SD card is still encrypted. Is there a way ...
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1answer
2k views

Encrypting sensitive data in software and storing/decrypting it on a server

I have searched IT Security and Google for something similar to this, but wasn't able to find anything remotely related to what I'm doing. I'm developing software which has 2 parts - a C# program run ...
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1answer
708 views

PKCS#7 message constructed by our code, any weaknesses in the output?

We have this as the PKCS#7 encrypted message. We would like to open this up for review and analysis here, for people to poke holes. This sample is generated via test certificates and keys. The concern ...
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1answer
6k 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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6answers
2k views

How to “demonstrate” man-in-the-middle attack?

I'm TAing a particular course on system security. A specific example is transitting the password in plain text when developing a web application (as part of a class project). Over the years a bunch ...
5
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3answers
1k views

Are private keys generated by different software packages compatible?

I know that GnuPG follows the OpenPGP standard, but if I generate a public/private key pair using GnuPG and upload the public key to a key server, i.e. the one at MIT, or use it to sign files, ...
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5answers
53k views

Cracking CISCO ASA Passwords

I've got a copy of a Cisco ASA config and i want to crack the following example passwords I've got the following lines in the config ASA Version 8.4(2) ! hostname ciscoasa enable ...
3
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4answers
874 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 ...
5
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2answers
4k views

File security when encrypting files directly with the openssl command / and what about SHA1 hashing password first?

I've been using this command to encrypt files for a while now: openssl aes-256-cbc -a -salt -in secrets.txt -out secrets.txt.enc Then I type in a password. Can someone tell me, roughly speaking, ...
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2answers
445 views

What is a better practice - RSA Encryption vs Windows authentication

I have two machines running windows OS with IIS and window OS with MS SQL. In the production web.config file I configure the IIS to use a user name and password when connecting to the DB and then I ...
0
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2answers
174 views

How can I encrypt something user provided without risk of the key being exposed?

So, let's say I have a theoretical service. User has some text they want to encrypt. They pass it to me, and I encrypt it. Then, only I should be able to decrypt it afterwards. Another kicker, it must ...
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2answers
108 views

How can I set up signed downloads?

Scenario I have a web server that authenticates and redirects from HTTP to HTTPS. Clients can then view available "downloads" in their account. I want to be able to sign these download links - as in, ...
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4answers
487 views

Strategies to store/remember very long password?

If future proof encryption is - in theory - possible it will require long password. What are some of the strategies for storing or remembering very long - in this case rarely used - password? For ...
6
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1answer
2k views

Is there cryptographic material in a phone's SIM card that can be used with RSA encryption?

Given that a smart card stores a private key that can't be extracted, it appears that a SIM card is similar to a smart card in these respects. I need to store (or use an existing) private key on a ...
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3answers
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Encrypt data within mobile app and send to web service

I'm developing a mobile application for Android and iOs. What is best practice when it comes to data encryption within the mobile application which will be sent to a web service? Basically I will ...
3
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3answers
194 views

Is it safe to mix authentication methods?

Is it a good idea to "combine" authentication methods? Example we can use username/password method to authenticate a user from a server. What if we used this as a first authentication step to get ...
7
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1answer
4k views

Android / CyanogenMod encryption vs GNU/Linux

Hi I am trying to understand how encrypting an Android based phone works compared to a GNU/Linux host which relies on LUKS dm-crypt. Here is what I understand: Encrypted LVM on GNU/Linux is an ...
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1answer
424 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 ...
6
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2answers
2k views

Is it reasonable to prevent timing attacks by using fixed processing time

I have systems that perform cryptographic operations within a SSL/TLS tunnel. My concern is that I may leak timing information when encrypting, decrypting, or hashing. Part 1 Is it a good idea to ...
14
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2answers
17k views

Is it possible to use S/MIME in the web client of Gmail?

I could not find any options in the web interface of Gmail. All I could find was a Firefox plugin to use S/MIME with Gmail, but it seems to be outdated.
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3answers
1k views

How practical/important is the Lucky Thirteen TLS attack?

I was reading this article which talks about a new attack against TLS being called Lucky Thirteen. It claims to allow repeatable MitM attacks against HTTPS connections. It's described as being fairly ...
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1answer
125 views

Auto encrypt chunks of content for backup, best practice?

I'm just curious and it's more like a mind game, I'm not into cryptography. How would one encrypt data that's constantly generated? Put the data automaticly into chunks encrypt the chunk and send it ...
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2answers
174 views

Need a time consuming symmetric encryption

I have a database with millions of entries, each entry encrypted with a (different) password. Normally, only one entry is needed at a time. If somebody steals the database, I want to make it hard for ...
3
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2answers
461 views

Securing Time Sensitive Data

I have a number of time sensitive, embargoed pieces of information that I need to distribute over the Internet and have received at a precise time. I'm currently dealing with the problem by uploading ...
5
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5answers
248 views

How to avoid to lose data encrypted because it was encrypted by no longer supported software?

How can I avoid losing data that is encrypted using methods that may become obsolete? I have valuable family records I wish to secure, so I plan to encrypt them before putting them in long-term ...
2
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1answer
363 views

Credit card data - sharing and storage [duplicate]

What is the industry standard for sharing credit card data between client (thin & thick) and server?
3
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0answers
240 views

Utility to hide several encrypted messages in single file [closed]

I am interested, are there existing utilities/projects under way devoted to combining encryption and steganography. I would like to - combine two or more messages, encrypted with separate ...
6
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5answers
3k views

Does a binary executable have to have some critical plain-text components?

When companies package binary executables, they are often encrypted, compressed, scrambled, and otherwise made so that your lazy hacker can't simply open the program up in Notepad++ and see the code. ...
2
votes
2answers
273 views

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 ...
4
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1answer
398 views

Saved passwords (use case)

I have a program in which a user enters a password, and the user data is stored encrypted using AES-128. The data and passwords must be stored together. Both the data and the password are encrypted ...
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1answer
603 views

Secure Web application Password vault/manager [duplicate]

I would like to build an open source online password vault which allows users to securely store their passwords, like Keepass or roboform, but where a user can access their passwords through a website....
4
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3answers
1k views

Determine hashing algorithm only with known input and output

Given the input: test A system generates the following output hash: 0x001F41B6A0534D3B851D69EFE6237F550100000010D5F4FC65E64BCFDBF2590212E4411C44942C6C734C00ACFE13B958DCAB3614 I do not know ...
4
votes
3answers
966 views

How to secure a truecrypt container allowing access with multiple SSH public keys?

I would like to create a TrueCrypt container which can be accessed by multiple people. The container itself can be stored anywhere, e.g. in a shared folder in Dropbox or Google Drive, ... I would ...
1
vote
1answer
2k views

Picking an encryption algorithm for auth tokens passed via AJAX

I'm looking for a low CPU intensive encryption algorithm, to pass around session authentication tokens. As an example: The user will login in to the website (via OAuth, whether by the site as ...
12
votes
1answer
2k views

How to study the packets sent by a keylogger

One of my friends runescape account got hacked through key-logger. He downloaded a runescape gold generator from a file sharing site and tried to use it. I have a strong doubt that it is a key-logger. ...
9
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3answers
3k views

Encrypting user data using password and forgot my password

I am planning to do a web application which stores a lot of personal stuff (info, photos...). And to give users a sense of protection, I want to encrypt the data before storing it to the database. So,...
4
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1answer
2k views

How to make a secure key distribution scheme/protocol?

We are building a data processing platform on Amazon AWS. We are going to store sensitive data in the S3 (encrypted) and then the Amazon EC2 node is going to be utilized to process this data. We are ...
3
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1answer
2k views

How to secure or (Ensuring Integrity) of Web Data in transit and in store?

Consider (usual scenario) You own a Shopping Cart Website and hosted on Internet, now, your hosting company provides you database to store your data. If talking about security, we need it for: ...
9
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3answers
24k views

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?