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5

Yes. Most private keys have an easily identifiable format. If its say an RSA private key generated with openssl, they have a specific format e.g., will always start with the same three bytes depending on key size: 30 82 01 (for 768 bit key or MIIB in base64) 30 82 02 (for 1024 bit key or MIIC in base64), 30 82 04 (for 2048 bit key or MIIE in base64), 30 ...


4

"Additional authenticated data" is whatever you wish it to be. GCM is an authenticated encryption mode in which the inputs are: a key K suitable for AES (128, 192 or 256 bits); a 96-bit IV; some plaintext data P whose length is at most 239-256 bits (i.e. about 68.7 gigabytes); some additional data A whose length is at most 264 bits (i.e. about 2.3 millions ...


3

Here's a possible website you can use to find out more: http://www.openculture.com/2013/01/the_enigma_machine_how_alan_turing_helped_break_the_unbreakable_nazi_code_.html A Summary: Legitimate Method: The Nazis released a monthly code sheet with the appropriate settings for each day of that month. Once you knew the settings, you could type in the nonsense ...


3

Exact answer depends on the involved mode of operation, but most of them begin to exhibit unwanted structure when about 2n/2 blocks have been processed, when the underlying block cipher uses n-bit blocks. The fundamental reason for this is that a block cipher like AES is a permutation: any two distinct input blocks are encrypted into two distinct output ...


3

As others have explained, the "period" measures the number of output bits (or "words", depending on terminology) after which the PRNG begins to repeat itself. For some PRNG this is relatively ill-defined. A PRNG is a deterministic algorithm with a state (the contents of its internal buffers and counters and variables). The sequence of subsequently emitted ...


3

Every PRNG has an internal state which is used to compute the next output deterministically. The state is updated after each output. If the state has n bits after at least 2^n outputs the internal state must repeat which means that the PRNG produces the same sequence of outputs. Roughly speaking, the number of outputs until the internal state repeats is the ...


2

The Nazis had physical code books they would distribute. They would determine the Enigma settings for the day. Then using those settings, each message would start with a message key setting the starting rotor settings for the rest of the message. These were useful as cribs for breaking out messages since all messages the Nazis sent for a day started using ...


2

There is an informational RFC for use of OpenPGP keys in SSL/TLS; as the RFC says: The term "OpenPGP key" is used in this document as in the OpenPGP specification [RFC4880]. We use the term "OpenPGP certificate" to refer to OpenPGP keys that are enabled for authentication. That's what these keys are for: usages as part of authentication protocols which ...


2

The chances of this happening by chance are zero. You have either: Found the old private key you thought was lost (hidden file?), or Used a deterministic key generation mode which takes user-supplied entropy (passphrase). If you use the same entropy you will get the same key, or You've got a completely borked install which always returns the same random ...


2

If you do not have access to the source code, you will have to make multiple attempts to see if there are any patterns in the token generation. If it is a basic incrementor, this may be easy to defeat. You can take the length of the token into account as well. Here are some OWASP guides on the topic, which may be of use: Testing for weak password change ...


1

If you browse the Crypto.js source, it does not implement TLS (or SSL), and as such can't implement the TLS extension Heartbeats. By not implementing TLS or Heartbeats, it can't have the Heartbeat vulnerability exploited by Heartbleed (trusting the payload length in a HB request even if its longer than the original message and echoing back that much data). ...


1

There are a lot of ways to look at security questions, and rarely a "right" answer. In this case, you might want to start by listing out what the basic goal(s) of the cryptosystem is/are; i.e., "what's the point?". From there, you can consider what is not being fulfilled if the hash doesn't match. In this case, you're looking at a system that works by ...


1

I would advise against implementing this yourself. If you disagree, have a look at the current existing AES implementations; many libraries are available and it's likely that these will suit your needs. Have a look at Turning a cipher into a hashing function and Description of the AES cipher on Wikipedia if you're interested how the algorithm works.


1

From the example you show, you don't continue far -- what is shown is not a valid RSA key pair, only something which superficially looked like one in the eyes of the tool you used. Assuming you actually obtain a valid RSA key (you don't, apparently, but let's suppose that you find one), then your best bet would probably be to assemble the key with a small ...


1

The idea of PFS is that not all keys are equal, when considering risks of ulterior theft. A private key stored in a file may be stolen afterwards, e.g. if the disk fails and is carelessly discarded. On the other hand, a key which resides in RAM only disappears when the machine is shut down or rebooted, and thus is unlikely to be recovered by an hostile ...


1

A block cipher is a key-indexed pseudo-random permutation on the space of blocks: for a given key K, AES maps 128-bit blocks to 128-bit blocks, such that no two distinct input block values are mapped to the same output block value. Knowledge of K allows efficient computation of the inverse permutation as well. A block cipher can be used as a building ...


1

Your information is only secure as the server it lays on and the client machine and network is secure. It's always good practise to have different passwords for different websites. Reason behind it: Let's say you have same password for everything. Let's pretend "Facebook" got compromised with some vulnerability and got your password, they would able to get ...


1

Large corporations have an information security team and they are responsible for the different security policies and practices (password policies, key management, pentesting...). There are also a lot of recognized publications with good practices in security management they tend to follow (like ISO27001/ISO27002...). About VIP people, I don't think they ...


1

... I don't think there's a perfect one-size-fits-all solution. Different solutions are best in different cases. I think password safe's are a good balance of difficult passwords/not losing them, though obviously this makes the security of your password safe critical; it may even be worth having several password safes, perhaps for different classes of ...


1

If there is a method faster than brute force, it represents a weakness in the hash function. Essentially what you're looking for is a modified preimage attack, just for a group of hash values rather than a single value.


1

Schneier's blog has a couple of clarifying statements: It is more likely that the NSA has some fundamental mathematical advance in breaking public-key algorithms than symmetric algorithms. and I personally am concerned about any constant whose origins I don't personally trust. The justification of the former statement of course is very ...


1

Thomas has already written an excellent answer, but I thought I'd offer a couple more reasons why HTTPS is not more widely used... Not needed. As Jesper's answer insightfully points out "the majority of information on the web doesn't need security". However, with the growing amount of tracking taking place by search engines, ad companies, country-level ...



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