Cryptography is the practice and study of logical means used to achieve information confidentiality, integrity and authenticity. It covers, among other things, encryption (making some data unreadable except for those who know a given secret element, called a key), data hashing (in particular for ...

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3
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1answer
151 views

Would it be possible to add additional files to a password protected zip 2.0 file

I don't have the ability to determine/recover the master password for a production system that uses zip 2 archives. However, I need to be able to add new files to existing encrypted archives. There ...
31
votes
4answers
5k views

How does a hacker know how many times a password was hashed?

I've been reading a lot of questions about security and hash functions on this site and others. I am not an expert, just a curious mind and in my understanding the more iterations used to hash a ...
1
vote
0answers
22 views

Chosen plain text and chose ciphertext definitions clarification [migrated]

I am trying to understand a concept of CPA and CCA attack and I cannot get one thing from the definition. If an attacker can execute a CPA attack for something like Send 100 dollars to attacker ...
4
votes
1answer
64 views

How can I demonstrate that 3 independent root CAs validated my domain?

I am concerned about the hacking of a root CA and want to buy 3 SSL certs from completely different providers who will independently validate my identity. Then at presentation time, I will send all 3 ...
2
votes
2answers
57 views

SSL stripping in home network

I am trying to monitor the traffic of some "smart devices" in my home (TV, coffee machine, ...) but most of them communicate over SSL. What possibilities are there to look into SSL encrypted ...
-1
votes
0answers
14 views

Is 3DES is a weak cipher? [duplicate]

Our application runs on JBoss 6 + jdk 1.7. We use the jdk provided SSL provider. The server.xml file contains SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA in the cipher lists. Is it a weak cipher? Should we ...
1
vote
0answers
24 views

At what point is information encrypted when communicating from a C# program over HTTPS? [on hold]

So I was running a communication log on an application I support I noticed that within the log there was a request string that displayed my password in cipher-text, but the next request string down, ...
42
votes
6answers
7k views

Is using a public-key for logging in to SSH any better than saving a password?

Using a public/private key pair is fairly convenient for logging in to frequented hosts, but if I'm using a key pair with no password, is that any safer (or less safe) than a password? The security ...
8
votes
6answers
2k views

How do RSA fingerprints protect from MITM attacks?

I understand that RSA fingerprints are used to verify that you are really connecting directly to who you want to connect to, and not someone else posing as that site. Like when you do a git push, it ...
0
votes
1answer
98 views

Default Encryption - A Panacea or Placebo

I wrote this on LinkedIn - Discrete Discretion My first question is: Is it accurate to say that default encryption is a placebo? Will default encryption only make end-users think they are secure ...
4
votes
5answers
4k views

Does using WPA2-Enterprise just change the attack model vs WPA2-PSK?

As far as I can tell based on the reading I've done so far, WPA2-Enterprise uses the same encryption and security algorithms and methods as WPA2-PSK, with the addition of using another service for ...
1
vote
1answer
71 views

Which stream ciphers are supported in am335x cryptographic accelerator?

I want to use cryptographic accelerator in aes cfb mode [or any other stream cipher]. According to http://e2e.ti.com/support/arm/sitara_arm/f/791/p/156983/658334 link cfb is supported in am335x. I ...
4
votes
2answers
314 views

Using OAuth 2.0 without token storage

I am building a system for a product which requires authentication and authorization. Naturally I have chosen using OAuth 2.0 as it is a commonly used protocol and has proven to be useful. I am ...
5
votes
4answers
35k views

How safe is the 256-bit encryption used in bank transactions?

Most of the banks use a 128-bit or 256-bit encryption. What does this mean? Does it mean that the keys used in SSL are 128-bit long or what? If they are the SSL key lengths then 128 bit RSA keys are ...
0
votes
0answers
28 views

“encrypted using an obsolete cypher suite” - After using IIS Crypto best practices [duplicate]

I've used the IIS Crypto tool, using best practices and I still get "encrypted using an obsolete cypher suite" In Google Chrome. There's so many various cypher suites, and I'm yet to find a ...
7
votes
4answers
327 views

Renew digital certificate

If I have deployed a digital certificate on a webserver and if it needs to be renewed then what steps do I need to follow? Will I need to generate a new longer public key private key pair? Why do ...
1
vote
1answer
68 views

Does WebCrypto also mandate the crypto algorithms be implemented in Javascript?

I am trying to understand what WebCrypto means. From what I understand it is - A Javascript Crypto API spec that all browsers must (hopefully) support. Am I correct? If so are the crypto algorithms ...
0
votes
3answers
3k views

3 way authentication

Can someone please tell me what does 3 way authentication mean? I cannot understand this concept? Now if there are two people A and B A challenges B with a question B gives the answer and B ...
1
vote
2answers
74 views

Building an anonymous network

Imagine you're building Facebook, except you don't want to reveal user identity for posts and comments. You still want to verify each user's organization. For example, if the user signs up with ...
0
votes
0answers
25 views

breaking down RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING

So Java has a mode called RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING. What does that even mean? RFC3447, Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1, section ...
3
votes
2answers
204 views

How to store derby database encryption key in HSM?

The Derby Database supports encryption with a key or password. Traditionally this key is stored in the file systems, now I am looking to store and protect this key in the HSM instead, but I couldn't ...
-1
votes
1answer
66 views

Why not create your own encryption? [duplicate]

I am wondering if AES-128 and the likes were once broken and if they were broken because people knew they were trying to break AES then why don't we create our own personal algorithm to encrypt the ...
7
votes
6answers
1k views

Are there any hardware HSMs that can host/run custom applications using the HSM processor(s) within the hardened security boundary?

It seems that the majority of commercially available hardware HSMs are only designed to allow authenticated users to generate, store, and use cryptographic keys with various cryptographic algorithms ...
5
votes
3answers
3k views

Please help verify my understanding of Domain Validation (DV) SSL Certificate

This is what I understand so far from reading various knowledgebase and article about DV SSL. Can anyone please help clarify if any of these is wrong? DV SSL (and SSL certificate in general) is only ...
3
votes
1answer
133 views

Are there any passwords managers that use a second hidden encryption drive to hide passwords?

I've heard that encyption program, Truecrypt can create a hidden encrypted drive within an encrypted drive; and even if an attacker accesses the first encrypted drive he/she cannot prove the hidden ...
0
votes
1answer
122 views

RSA: same symbols in plaintext give same symbols ciphertext?

I just started studying Information Security, but I just ran this program: http://www.sanfoundry.com/cpp-program-implement-rsa-algorithm/ and faced this strange thing. For small keys (don't try to ...
8
votes
2answers
9k views

Recommended Cipher Suites for TLS 1.0, 1.1 and 1.2

There are a lot of cipher suites defined in the in the specifications itself of TLS 1.0, 1.1 and 1.2. And furthermore, there exist RFCs which add even more cipher suites to a specific version (e.g. ...
27
votes
4answers
46k views

Google Chrome “Your connection to website is encrypted with obsolete cryptography”

Google Chrome is showing new information in the certificate section. Is this a big deal? If so how can I fix it on the server end? EDIT: Thanks for the answers but I'm not skilled in cryptography ...
0
votes
0answers
38 views

Why isn't a table used to solve the large number factoring problem? [migrated]

Lots of modern encryption (RSA comes to mind) are based on the fact that factoring large numbers is hard. However, multiplying large numbers is much easier, and table lookups are very easy. Since ...
2
votes
1answer
453 views

How does signing work with Elliptic Curve Crypto?

So I have read up and have a decent understanding of how the crypto works with Elliptic Curve Cryptography. I also think I have an understanding of how signing works with things like Elliptic Curve ...
11
votes
3answers
11k views

What is the DUKPT Key Derivation Function?

I'm tasked with decrypting ciphertext acquired from an encrypted card reader. The card reader utilizes DUKPT(derived unique key per transaction) scheme and 3DES encryption. I don't have a problem with ...
1
vote
0answers
158 views

Storing Social Security Numbers in a Database

I'm developing an online application that needs the user's social security number. The application won't be processed on the web server so I'll be using an asymmetric key. So a compromised web server ...
0
votes
0answers
26 views

Triple-DES DUKPT CBC PIN variant vs Data variant

Does any know the difference between triple des dukpt decryption algorithm with PIN variant and Data variant? I have done Triple DES DUKPT PIN variant, which generate session key from KSN and BDK. ...
2
votes
1answer
78 views

Can TPM Storage Keys be Created Outside TPM?

I am interested in 'adding' preexisting keys to a TPM's storage hierarchy. An example of a desired key hierarchy can be shown as: (SRK)----->(User Storage Key)-------> User Working Key 1 ...
250
votes
13answers
29k views

How is it possible that people observing an HTTPS connection being established wouldn't know how to decrypt it?

I've often heard it said that if you're logging in to a website - a bank, GMail, whatever - via HTTPS, that the information you transmit is safe from snooping by 3rd parties. I've always been a little ...
73
votes
6answers
13k views

Why shouldn't we roll our own?

Why shouldn't we create our own security schemes? I see a lot of questions around here about custom crypto and custom security mechanisms, especially around password hashing. With that in mind, I'm ...
1
vote
3answers
44 views

Hashing Algorithms Costs vs Sleep

I understand most of the concepts behind hashing password but this one still escapes me. I understand that you want the hash to take some time ( a couple milliseconds) so the attacker can't ...
16
votes
5answers
3k views

The AES Crypt implementation hashes a password 8192 times to generate the key. Is this necessary?

I'm considering encrypting some small files (hundreds of kb apiece) using the AES Crypt reference implementation. Looking at the source, it seems that the encryption key is derived from the IV and the ...
2
votes
0answers
35 views

Let users sign in with eIDs - do I need government authorisation? (scope: all nation-states)

I've decided to launch a crypto-basic income system. Crypto UBIs are pretty popular now. For me, it seems like an open nation-state ID should exist by now (2015). However, Mike Hearn, Bitcoin ...
1
vote
1answer
79 views

How to encrypt or store data so that only a pool of processes can share it on Windows?

I am writing an application T1 which is using SQLite database to store some sensitive data and i am trying to encrypt it securely. The issue i am facing is that i don't want my symmetric key to be ...
0
votes
1answer
116 views

Does CryptoWall needs a internet connection to encrypt my files?

Does CryptoWall 3.0 use some resource on the internet to encrypt my files? I watched this video on YouTube - in this video a tool is used to sniff network traffic and find information about ...
19
votes
3answers
6k views

Cracking a linear congruential generator

I was recently listening to the security now podcast, and they mentioned in passing that the linear congrunential generator (LCG) is trivial to crack. I use the LCG in a first year stats computing ...
3
votes
2answers
321 views

Encrypting USB traffic: Is RSA necessary for AES session key exchange when using pre-installed secret keys?

I need a solution to encrypt USB communication between device A and device B. I was thinking about configuring each device with a secret RSA-2048 key, which would be used to exchange an AES-256 ...
1
vote
0answers
67 views

OpenPGP smartcards compromised by blackhat 2015 simcard hack?

This blackhat was a new sidechannel attack in the SIM-card AES encryption announced. I am currently using the OpenPGP smart/SIM-card version 2.1 to store my PGP-private keys, which is the same model ...
3
votes
2answers
423 views

Requiring 2 keys to access a content

I need to use an external service that can only be accessed by password. I don't like the idea of storing the plaintext password on the server, but AFAIK there's not much I can do. Considering this ...
4
votes
1answer
63 views

“MAC function must resist existential forgery under chosen-plaintext attacks”, what does that mean?

While reading about MAC (Message Authentication Code) I have faced this sentence: MAC function must resist existential forgery under chosen-plaintext attacks but I got confused. What does ...
2
votes
2answers
432 views

How do session keys in public key cryptography work? [duplicate]

I have read that a session key is symmetric, and it is encrypted by recipient's public key; When "Bob" receives a message, does he decrypt it with his private key and he's then in possession of an ...
5
votes
1answer
83 views

How to really treat security between peers in WebRTC

Recently I've been implementing WebRTC in my project and would like to add security and privacy to the couple. I then decided to search on and found something if it is really necessary to impose ...
1
vote
1answer
117 views

What is the most secure way to digitally communicate between the U.S. and China?

What is the most secure way for two people to communicate digitally when one person is in the U.S. and the other is in China (likely being monitored)? Updated: Here's some additional info: The ...
4
votes
3answers
84 views

Securely saving credentials for later plain-text authentication

I am developing a Django application where a user logs in with Kerberos, and then has accesses to a number of internal applications. One of these is a file application that connects to a server over ...