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103

The NSA is a composite organization, that comprises several sub-entities called "directorates" with various scopes and goals. The NSA, as a whole, is supposed to have a multitude of roles; its signal intelligence role (often abbreviated as SIGINT, i.e. spying) is the one most people talk about, and is supposed to be handled by the SID (as "Signal ...


66

Go for AES. AES is the successor of DES as standard symmetric encryption algorithm for US federal organizations. AES uses keys of 128, 192 or 256 bits, although, 128 bit keys provide sufficient strength today. It uses 128 bit blocks, and is efficient in both software and hardware implementations. It was selected through an open competition involving ...


50

Neither 3DES nor AES is breakable with current technology (and foreseeable technology as well). However, you may encounter some security issues with 3DES if you encrypt more than about 32 gigabytes of data with a single key, whereas the limit is much higher with AES (this is due to the block size; 3DES uses 64-bit blocks, which can lead to trouble after ...


34

The NSA convinced IBM that 56 bits was "enough": But whereas Lucifer had a key that was 112 bits long, the DES key was shortened to 56 bits at the request of the National Security Agency. from Practical UNIX & Internet Security In the development of DES, NSA convinced IBM that a reduced key size was sufficient from Data Encryption Standard - ...


14

Double-DES is two successive DES instances, while Triple-DES is three successive DES instances. We use 3DES and not 2DES because 2DES does not yield the security increase that you would believe. Namely, 2DES uses 112 key bits (two 56-bit DES keys) but offers a security level of about 257, not 2112, because of a "meet-in-the middle attack" which is well ...


12

Your private key is encrypted with Triple DES. While DES is easily broken, Triple DES is safe for now, especially in this context. AES was made to replace Triple DES not so much because Triple DES was broken, but because it was way too slow. In the context of private key encryption, a non issue.


12

NIST still recognizes 3DES (ANSI X9.52-1998) as a secure symmetric-key encryption algorithm when configured to operate as described in NIST SP 800-20. There are still Cryptographic Algorithm Validation Program (CAVP) certificates issued for 3DES in 2016. However, many open source projects (e.g. OpenSSL) and international certification standards (e.g. Common ...


11

Why is there des-ede3-cbs in my rsa private key? Because your private key is encrypted with that. As far as I know "DES" is an encryption standard from the seventies and it's considered broken. Yup. Pretty much. Consider reencrypting it with AES like so: $ openssl rsa -in desencryptedprivkey.pem -out aesencryptedprivkey.pem -aes128 EDIT 2015-06-29: ...


11

You should disable all triple DES ciphers because 192 bit triple DES keys only have about 112 bits of security and 128 bit triple DES keys have even less than 112 bit security, rather around 80 bits for the best attacks. Furthermore, triple DES only has an 64 bit block size, which is detrimental to security as well. There is a difference between the key ...


9

Key size was reduced to 56 bits because IBM wanted to fit LUCIFER on a single chip. LUCIFER then became DES. Because of the promising results produced by the LUCIFER project, IBM embarked on an effort to develop a marketable commercial encryption product that ideally could be implemented on a single chip. The effort was headed by Walter Tuchman ...


9

XOR is an operation that can always be reversed, all information is retained. It is as simple as that. Using AND and OR may result into information loss because you cannot tell if certain bits were either 1 or 0 in the operands. Playing a little with the python repl, we will use 19 (10011) and 5 (101) since these numbers make for good examples. Using OR ...


8

There is a concept of effective/actual key strength. For Double DES the effective key strength is 2^57 even though double DES uses 2^112 keys. The below example will make it clear. Assume that you are a cryptanalyst who has access to the plain text and encrypted text. Your aim is to recover the secret key. Assume AAA (plaintext) -> XXX (After 1st encryption)...


7

SHA-3 is a hashing algorithm. DES is an encryption algorithm. The two are not comparable. They do different things and do them in different ways. It's a bit like asking why your blender is faster than your bicycle.


7

Maarten's answer is excellent, but to expand on it a bit, you may want to read up on Meet-in-the-Middle attacks. The idea is, when you have a cryptographic cipher that consists of performing the same operation with two different keys in opposite directions, you can effectively search the key space from both directions at once, storing results (requires ...


6

This is not DES encryption. This is password hashing with the old DES-based "crypt" scheme. The terminology is, of course, very confusing. DES is an encryption function, but here we are talking about a hashing construction that happens to internally use the DES block cipher; if you look at it closely, then you may notice that the "key" used for that internal ...


6

The encryption key was never published and triple DES itself is strong enough to not brute force, so you have to use some of the other mistakes to attempt to recover your password. Your options are: exploit the fact that they used ECB and use the hints. To do this you will find your encrypted password and see if other users had the same block. For example, ...


6

Your question appears to have nothing to do with certificates or hashes. Neither one involve symmetric ciphers (like DES or AES) at all. The actual answer is just a matter of how Outlook (or Mail.app) is configured on each machine, nothing more. I don't know how to control the ciphers used on Outlook for Mac, but here are the steps for Outlook 2013 on ...


5

Though the details are not published yet, the currently known information points at the following: some sensitive operations are protected with some encryption and a MAC, both relying on carrier-specific choices of algorithms and key lengths. However, some carriers apparently rely on DES whose key size is relatively small (56 bits), making key recovery in ...


5

Confusion and diffusion aren't attributes provided by DES, but rather the building blocks of creating a cipher like DES. In the case of DES, the confusion step is the S-box substitution, while the diffusion step is where the output of the S-boxes is rearranged according to the P-box permutation rules. See Wikipedia: DES for the actual details.


5

Yes, like all block ciphers, DES is a PRP. That is a Pseudo Random Permutation. A permutation is a reordering of all possible input values. In the case of DES there are 2^64 possible input values as the block size of DES is 64 bits. If you have a key and DES in encrypt or decrypt modus then the key will indicate a reordering of all 2^64 possible values. In ...


5

DES-CBC3, is a shorthand for a few suites in OpenSSL (that doesn't always have an exact one to one mapping between the name used and the suite used, it constructs it from the name and the type of key used for authentication). Nowadays, this name almost always means a suite documented in RFC 6101 where it is called, a slightly better name : ...


4

Well, if you are doing plain old single DES, it doesn't matter -- 56-bit DES keys can be easily brute forced. The EFF DES cracker could break a 56-bit DES key in under a day way back in 1999. Generally, yes its best to have a totally random key for symmetric encryption (block ciphers) as there will be no shortcuts when brute-forcing the key. In practice, ...


4

I would suggest John the Ripper. Get a large dictionary file and run it through John. You could even split it among multiple machines (possibly in the cloud) as the problem is very parallelizable. John can even do variations on dictionary words like substituting 0 for o. For more info, see this article. If you have access to a GPU, oclHashcat looks ...


4

To understand what happens with Double-DES, consider the meet-in-the-middle attack (completely unrelated to "man-in-the-middle attacks"). Setup: there is double-DES, where a data block is encrypted with key K1, then again with K2. The attacker could have access to two plaintext/ciphertext blocks: attacker knows A, B, C = EK2(EK1(A)) and D = EK2(EK1(B)). ...


4

8/10 bytes. The standard has always had KSN 10 bytes (80 bits), but allowed smaller values padded on the left with 0xFF, and many people did or do use 8 bytes. I'm not in a position to say there's a clear pattern either way. If any of the devices (or systems) you expect to deal with are limited to 8 bytes, then yes use 8 bytes. As below, it's basically ...


4

In computing, Real-Time means the study of systems that must operate within strict time constraints. This is a very large class of systems, and it tends to include most applications with a user interface. For instance, if you go to Youtube and view a video, then this is a real-time application: the downloading, decompression and display of the pictures must ...


4

Back in late 1980s the NSA had a branch called the National Computer Security Center (It may still exist today). The job of this "center" was to help enterprises on the budding forefront of information technology stay secure. Some of the main things they did were: test hardware of major vendors for defects that could leave them vulnerable, test software of ...


4

I agree with your analysis of the reasons why police departments and other agencies would use "weak" encryption products with their radios: simply because as of the current day encryption crackers are rarely used by common criminals that listen to radio transmissions of such agencies (they perhaps use analog/digital radio scanners, but such scanners can ...


4

Recovering the key for double-DES takes three steps. Given the plaintext and the ciphertext you do the following: Encrypt the plaintext with all 2^56 possible keys and write down the results Decrypt the ciphertext with all 2^56 possible keys and write down the results Check where the results are the same. That is your key. Note that all you had to do to ...


4

In its plain form, CBC-MAC is vulnerable to "length extension attack", where you just add some blocks at the end. So in order to stop people from doing that, you need to somehow mark the final block as indeed the final block. And not treat it like any other block. Wikipedia lists two ways: either prefix with block count, or encrypt final block with ...


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