I need to store some sensitive data by encrypting it with atleast 128 bit key. I investigated into javax.crypto package and found that there are certain Cipher names, like
PBEWithMD5AndDES or PBEWithSHA1AndDESede which provides encryption upto 56 bit and 80 bit (http://en.wikipedia.org/wiki/DESede).
I referred other guys posts but those are mainly using RSA and in my understanding RSA is generally suitable for encrypting the communication data (with private-public key pair). My need is different, I just want to store the data and retrieve it back by decrypting it. Therefore I don't need any private-public key pairs.
Please let me know if you have any idea about this.
Use Advanced Encryption Standard (AES). It supports Key lengths of 128, 192, or 256 bits.
The algorithm is simple. The Sun Java website has a section explaining how to do AES encryption in Java.
From Wikipedia...
... the Advanced
Encryption Standard (AES), also known
as Rijndael, is a block cipher adopted
as an encryption standard by the U.S.
government. It has been analyzed
extensively and is now used worldwide,
as was the case with its
predecessor, the Data Encryption
Standard (DES)...
So as a rule of thumb you are not supposed to use DES or its variants because it is being phased out.
As of now, it is better to use AES. There are other options like Twofish, Blowfish etc also. Note that Twofish can be considered as an advanced version of Blowfish.
I have had good success in the past with http://www.bouncycastle.org/ (they have a C# version as well).
You need to download and install the unlimited strength JCE policy file for your JDK. For JDK 6, it is on http://java.sun.com/javase/downloads/index.jsp at the very bottom.
Combining 3 different replies gives what I think is the correct answer.
Download encryption libraries from Bouncycastle then you need to download the "Unlimited Strength Jurisdiction Policy" from Oracle (the files are at the bottom of the download page). Make sure you read the Readme-file on how to install it.
Once you have done this, and using the sample code supplied with the Bountycastle package you should be able to encrypt your data. You can go with a tripple DES implementation, which will give you 112 bits key (often referred to as 128 bit, but only 112 of them are actually secure), or as previously stated, you can use AES. My money would be on AES.
I'm not a crypto expert by any means (so take this suggestion with a grain of salt), but I have used Blowfish before, and I think you can use it for what you need. There is also a newer algorithm by the same guy called Twofish.
Here is a website with a Java implementation, but be careful of the license (it says free for non-commercial use). You can find that link also from Bruce Schneier's website (the creator of both algorithms).
Thanks Michael, after trying out many things in JCE, I finally settled for bouncycastle.
JCE supports AES for encryption and PBE for password based encryption but it does not support combination of both. I wanted the same thing and that I found in bouncycastle.
The example is at : http://forums.sun.com/thread.jspa?messageID=4164916
Related
This may be a noobie question but I'm confused on how providers work. I've tried reading this https://docs.oracle.com/javase/7/docs/technotes/guides/security/overview/jsoverview.html but it doesn't quite make sense to me. Say we have:
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding", "BC")
and
Cipher cipher= Cipher.getInstance("AES/CBC/PKCS5Padding")
According to the link it sounds like the provider indicates the implementation that is in use but isn't AES/CBC/PKCS5Padding basically the same independent of the provider? In the example does bouncy castle (what I'm guessing "BC" corresponds to) happen to have a more efficient algorithm than the default implementation? Thank you for your time.
isn't AES/CBC/PKCS5Padding basically the same independent of the
provider?
Yes, it is.
In the example does bouncy castle (what I'm guessing "BC" corresponds
to) happen to have a more efficient algorithm than the default
implementation?
Probably not. In the case of AES in particular, recent Oracle providers are likely to be dramatically faster than Bouncycastle due to their use of native AES hardware when available.
So why specify the provider?
Ok, I know you didn't ask that but that seemed to be where you were headed. In most cases you should not specify a provider. The general rule is to avoid specifying a provider unless you have a good reason to do so. Leaving the provider unspecified increases portability.
Unfortunately, there are some cases I've encountered where you probably need to specify the provider. The abstractions provided in the JCE just do not cover all the situations that arise in practice. If you run into one of those it's best to ask a separate question.
I inherited a Java (Spring) project in its maintenance phase, that just went through Veracode for the first time, and the only High flaw we have remaining is one reporting a "weak or broken" encryption algorithm. I'd prefer to spend the time learning more about cryptography, but this project is live in the wild so I need to start with a more immediate solution to get this application secured.
Here is the line Veracode is reporting specifically:
Cipher cipher = Cipher.getInstance("PBEWITHSHA1ANDDESEDE");
Veracode offers no information on:
Why this algorithm is broken/weak
Which algorithms might make for sufficient substitutes
Any other concerns to be aware of when selecting an appropriate algorithm
What could I replace "PBEWITHSHA1ANDDESEDE" with? Would that necessitate other refactors, or is it as simple as a string literal swap? I'd love to give more specification to help us narrow down which encryption algorithm would be best, but since Veracode isn't providing any, the only specification is, "encryption algorithm that satisfies Veracode."
Why this algorithm is broken/weak
It is mainly broken because it uses PBKDF1 instead of PBKDF2 (or another/better Password Based Key Derivation Function). Using triple DES is also a small weakness as it may only offer about 80 bits of security in certain settings. SHA-1 is broken and it may well be a reason why Veracrypt mentions "weak or broken" encryption algorithms, but actually the use of SHA-1 in a key derivation function is considered secure.
Which algorithms might make for sufficient substitutes
If you want to rely on build in functionality then PBEWithHmacSHA256AndAES_128 would be a direct replacement. Other schemes could include other derivation functions such as bcrypt, scrypt or Argon2 and other modes of encryption such as AES-GCM.
Any other concerns to be aware of when selecting an appropriate algorithm.
CBC as used in above schemes is not secure for transport mode security unless a MAC (message authentication) is added; it is only secure for in-place encryption where padding oracle attacks don't apply. This is also the case for your current scheme though.
Your scheme still relies on password security, which can be very weak in itself. Generally you want to use a high iteration count / work factor and / or make very sure that the password / pass phrase has sufficient strength.
No PBE scheme (including the one you are already using) is an implementation requirement for Java compatible JRE's. Although alternate JRE's probably will provide an implementation I would not count on it being present or correctly implemented in Java versions of other suppliers.
I'm working on a mobile App which is to be build in Android (Native) , iOS (Native) & PhoneGap. For security I'm already using SSL, but as per client requirement another encryption is to be implemented in all webservices( Mobile end and Server) . But I'm unable to implement encryption which works well in Java, Objective-C and JavaScript.
I could manage to get AES-256 working in all the platforms , but it works very slow in Android. Library used for the same was RNCryptor.
Can you please suggest me any Encryption/Decryption library which is compatible along at least Java & Objective-C.
AES-256 a correct choice and should not be a performance problem. Most cpu chips include special instructions to allow faster implementations, Apple ARM chips do as do may Intel chips. If you are going to claim that encryption is slow for an implementation you need to supply test times for all platforms, generate them and post them.
Obtaining the same results from encryption, AES-256 in this case, is simply supplying the exact same inputs with the exact required lengths and exact same options--that is all.
Providing secure encryption is more than just a key, data and an AES-256 library. There needs to be an iv, if the key is week it needs to be extended, passwords are generally extended with PBKDF2 or it's like. These require more information to be added to the encrypted data that is passed. There is also data padding such as PKCS#7. RNCryptor handles all this but for interoperability requires the other-end to use the same scheme. Then there is the issue of securing the encryption key and exchanging it with the other-side.
I have some text that is in a file. I want to encrypt this file so that an end user can not read or write to this file, but the application can read it. There can be a stored secret in the application because it is being secured in another way.
What type of Encryption support these requirements?
I was thinking of AES. I do not know much about encryption, and was looking for a starting point. An algorithm or a framework suggestion would be great.
One last note, the code is in Java running on a Windows and Linux environment.
Since you've tagged the post as "Java" - I'd recommend looking at the "Java Cryptography Extension" (JCE). Since J2SE 1.4 it's been bundled with the SDK and JRE.
And of course, a requisite example and overview of using AES in the JCE.
If the application can read it, the application has a key in it. And if the application has a key in it, a sufficiently energetic user can find that key and use it for themselves. Or spy on memory and see the decrypted version.
AES or RSA would be just fine. An important thing to notice though is that once your program decrypts data, a reverse engineer would easily recover the plaintext without any knowledge of the key or algorithm of encryption.
I need to programatically encrypt a directory of files, like in a .zip or whatever. Preferably password protected obviously.
How can I accomplish this, and WHAT IS the BEST encryption way to do it, if applicable?
Programming language doesn't matter. I am dictioned in all syntax.
How can I accomplish this, and WHAT IS
the BEST encryption way to do it, if
applicable?
tar and gzip the directory.
Generate a random bit stream of equal size to the file
Run bitwise XOR on the streams
Only truly secure method is a truly random one time pad.
I still say 7-zip is the answer. It hasn't been "cracked".
The OpenSSL library has a variety of block cipher implementations including the well-known AES. It has both a function-call interface (for use with languages like C/C++) and a program-call interface (for use in shell scripts). http://www.openssl.org/
4096-Bit (Open)PGP: 'Pretty Good' Privacy !
GnuPG is the GNU project's complete and free implementation of the OpenPGP standard as defined by RFC4880 . GnuPG allows to encrypt and sign your data and communication, features a versatile key managment system as well as access modules for all kind of public key directories. GnuPG, also known as GPG, is a command line tool with features for easy integration with other applications. A wealth of frontend applications and libraries are available. Version 2 of GnuPG also provides support for S/MIME.
libgcrypt:
http://www.gnupg.org/related_software/libraries.en.html
Edit:
BouncyCastle now has OpenPGP support.
http://www.bouncycastle.org/
Use AES. You'll find implementations in your favourite programming language by asking google for AES encryption + myfavouritelanguage.
If you're using .NET, why not use a free compression framework (http://www.icsharpcode.net/OpenSource/SharpZipLib/) that supports Encryption?