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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16 views

OpenSSL -nopad with ECB mode

I was just trying to check if OpenSSL does use PCSK5 as documentation states when I got the following problem. I first encrypted a plaintext and encrypted it using DES-ECB. I was expecting to see ...
-4
votes
0answers
53 views

Session Hijacking over HTTPs possible or Not? [on hold]

session hijacking like amazon possible if the server remains in HTTPS? what are the circumstances under which such attack is possible (including network pre-requisites).
2
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2answers
43 views

Expand key to size of plaintext

I'm taking a cryptology course, and one thing that popped up as an idea was the following: Can't one take a "master" key, and generate a key that is as big as the plaintext, to encrypt the plaintext ...
0
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1answer
75 views

Can anyone with access to root CA private key decrypt HTTPS traffic?

Can anyone with access to root CA private key decrypt HTTPS traffic of sites using certificate signed by that CA ? and if yes do he need to be man-in-the-middle or just monitoring traffic is ...
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2answers
67 views

How is a cypher algorithm verified?

I've always thought about how the symmetric cyphers are verified. Let say I would invent a new cypher. (actually I don't :-)) How should I rationalize its security to the public? As far as I saw ...
1
vote
1answer
21 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 ...
9
votes
4answers
1k views

Location to store an encryption key

I'm building a secure system which stores messages on a server in a Postgresql database. The messages are stored encrypted with PHP's openssl_encrypt() function with the AES-256-CBC method. At the ...
28
votes
9answers
13k views

Feeding /dev/random entropy pool?

Which way of additionally feeding /dev/random entropy pool would you suggest for producing random passwords? Or, is there maybe a better way to locally create fully random passwords?
1
vote
2answers
61 views

Real-world applications of Differential Privacy?

Differentially private techniques guarantee privacy while often permitting accurate answers ...this is something I have been reading up on lately as a means of preserving user ...
0
votes
1answer
41 views

Secure shuffles and the rand() function

I'm trying to understand one aspect of a secure shuffle using Fisher-Yates. For reference, here is Fisher-Yates to shuffle an array x of n elements (numbered from 0 to n-1) (from Securing a Shuffle ...
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1answer
318 views

Don't use encryption without message authentication

The text is taken from the famous answer: Lessons learned and misconceptions regarding encryption and cryptology: Don't use encryption without message authentication Alternatively, you can apply ...
2
votes
1answer
420 views

adding certificate that resides on smartcard to the microsoft store with private key ownership

how can we solve CryptAcquireCertificatePrivateKey fails with 0x8009200B when adding certificate from smartcard to local user store? in an enrollment system where users generate smartcard certificate ...
-5
votes
1answer
34 views

Difference between secured crypto-processor and cryptoprocessor [closed]

Can some one please tell me what is the difference between secured cryptoprocessor and a cryptoprocessor? From the wiki page of Secure Cryptoprocessor Unlike cryptographic processors that output ...
2
votes
2answers
1k views

Cryptography behind chip based credit cards (smart cards)?

Why are chips safer than magnetic stripes? The answers to the above question explain that the chip based cards can not be cloned as the "secret number" is embedded in the chip and protected by the ...
0
votes
2answers
106 views

Why does the finance industry uses 2TDEA instead of 3TDEA?

Why does the finance industry uses 2TDEA instead of 3TDEA; is there any historical reason or technical limitations like the support by HSMs used in the industry? The paper referred to here says ...
5
votes
2answers
935 views

Generating one-time tokens from API-key?

I have a web-site for which I'm building a Drupal module that allows the users of that Drupal site to navigate to my web-site directly from the Drupal site. I intend to distribute secret API-keys to ...
1
vote
3answers
245 views

Java AES encryption output length

I am trying to encrypt few database columns (string values) using Java AES algorithm. This is to protect certain sensitive data. For some users these data should decrypted. In Java AES encryption, if ...
23
votes
6answers
19k views

Most secure password hash algorithm(s)?

What is/are currently the most cryptographically secure hashing algorithm(s)? (available in PHP) Speed is irrelevant, because I'm iterating the hash over a fixed time (rather than a fixed number of ...
1
vote
1answer
40 views

Connecting to Oracle Database from VBScript - Hiding Credentials

At work our first level support uses a ticket management system that allows us to add extra functionality via VBScripts that the application invokes. First level support also receives quite a few ...
0
votes
5answers
842 views

What voip client support manual encryption?

In pidgin there is a plugin that we can use to encrypt our messages in chat windows .. Is there anything simular for voip (pc to pc) ? any client that support manual encryption for voice data?(linux)
7
votes
4answers
967 views

Why secure encrypted data consistency by strong hashing?

Consider the SSH protocol: the SSH packet is like [data, SHA1(data)]. The packet is entirely encrypted by a block cipher. The question is, why do we need a strong hash to protect the packet ...
1
vote
1answer
108 views

Efficacy of self-made ransomware protection

I was recently wondering about how to circumvent malware such as the infamous Cryptolocker a while back and was wondering about the efficacy of having a set of files with known content in a known ...
553
votes
21answers
107k views

XKCD #936: Short complex password, or long dictionary passphrase?

How accurate is this XKCD comic from August 10, 2011? I've always been an advocate of long rather than complex passwords, but most security people (at least the ones that I've talked to) are ...
1
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1answer
204 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 ...
3
votes
4answers
20k 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
1answer
65 views

Encrypting the salt with password [duplicate]

Salts are stored in the plain text and readily available with the hashed passwords if the password database is compromised. What if we encrypt the salt using password itself? Doesn't it make offline ...
0
votes
1answer
88 views

rolling code & keyless entry system [closed]

The security industry typically uses rolling code algorithms to authenticate sender & receivers in keyless entry systems, which is called RKE (ex: KeeLoq). In key-less smart key car system, The ...
0
votes
1answer
63 views

Key Exchange using RSA

I'm trying to do key exchange using the following scheme. Server generates an RSA-2048 key pair and sends the public part to the client Client generates an RSA-592 key pair (I have to use RSA-592 ...
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votes
3answers
55 views

Full control on cryptography vs relying on external certificate [closed]

I have a question with regards to having full control on the cryptography which you will be using for your own application vs relying on external entities such as certification authorities? What are ...
1
vote
1answer
118 views

How to safely use a Key Derivation Function to secure private data - need guidance

I have some secure data created in my client app which I wish to store on the server as backup for the user. The user already has a password to authenticate with the server. The password is never ...
7
votes
3answers
3k views

When changing a PGP passphrase, does it only affect the private key?

I am beginning to use GPG for email encryption. If I use gpg --edit-key [keyID] to change the passphrase, what files will this affect? Will it only affect my private key, and thus I only need to ...
7
votes
4answers
4k views

Generate a PGP key with more than 4096 bits?

I would like to know if generating a PGP key with a number of bits higher than 4096 is possible and if so how?
3
votes
2answers
65 views

Link Layer authenticated encryption vs authentication

Many security articles discuss about adding an extra layer of security at the link layer by either authenticating the data at the link layer authenticating and encrypting it. If we have ...
35
votes
7answers
3k views

Why is HTTPS not the default protocol?

Why is HTTP still commonly used, instead what I would believe much more secure HTTPS?
72
votes
6answers
23k views

Password Hashing add salt + pepper or is salt enough?

Please Note: I'm aware that the proper method for secure password storage hashing is either scrypt or bcrypt. This question isn't for implementation in actual software, it's for my own understanding. ...
0
votes
0answers
13 views

gpg2 - no option to select aes block cipher and outdated use agent? [migrated]

With OpenSSL, I can select a what type of block cipher to use for encrypting a file. For example, if I want to encrypt a file with AES256 CBC block cipher mode: openssl aes-256-cbc -a -salt -pass ...
0
votes
1answer
58 views

Publicly Available API + Sensitive ID/Key Transmission Over HTTP

I've run into a predicament... I'm developing a mobile application that utilizes a server for various things. One portion is that it stores an id/key pair related to accessing and processing ...
18
votes
4answers
71k views

How can I export my private key from a Java Keytool keystore?

I would like to export my private key from a Java Keytool keystore, so I can use it with openssl. How can I do that?
2
votes
2answers
80 views

Securing fingerprint templates stored on web authentication server

I have a multi-factor web authentication server, that in addition to regular passwords uses fingerprints for user authentication. Can anyone think of a security flaw in the following scenario: I ...
2
votes
1answer
266 views

Is my AES/CTR/RIPEMD encryption correctly implemented?

Below is my encryption implementation in PHP. It's based on mcrypt, and uses AES-128 in CTR mode along with a RIPEMD-128 HMAC for integrity checking. For brevity, I've inlined the functions for ...
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votes
3answers
103 views

Is information security based entirely on mathematics [closed]

I started to show interest in information security few months ago, the more I read the more I think it's all about mathematics not information techonolgy. I mean the whole thing is based on encryption ...
-2
votes
2answers
129 views

Is this adaptation of using a One Time Pad safe?

For example, lets say there are two people named, Bob, and Jim. Bob wants to send Jim a long secret message, and he decides to use a OTP to encrypt his message. Both Bob and Jim know a secret ...
2
votes
0answers
7 views

Viewing and listing keys in MSCAPI CSP containers [migrated]

I have a MSCAPI container created and hosted within a Windows Server 2003 environment. How do I use the command line to list keys and their details within the container onto the command line ?
15
votes
4answers
2k views

Why should I sign data that's already encrypted? [duplicate]

My question is about the difference between signing and encrypting. Why would you still sign something if you are already going to PKI encrypt it? Doesn't the PKI encryption inherently provide ...
7
votes
1answer
250 views

Collision attacks on OCB?

I've been looking into the OCB cipher mode and everything I hear sounds good. I was planning on implementing it. Everything except for this lone voice, that is: Collision attacks on OCB: We ...
0
votes
1answer
35 views

Forward Secrecy not supported with referenced browsers?

I am running a scan against one of our servers from the Qualys SSL tester site and it says that my server "does not support forward secrecy with the referenced browsers". What exactly does that mean? ...
15
votes
4answers
2k views

In what ways does Full or Partial Homomorphic Encryption benefit the cloud?

Can someone explain, in plain English, the practical ways FHE and PHE can be leveraged in the cloud? Some interesting (and confusing) links include this Microsoft Research PDF and this wiki entry. ...
3
votes
3answers
167 views

Is there any security gain / risk by adding additional padding (beyond what is required) when using AES-256 to encrypt very short strings?

I would like to encrypt some authentication tokens using AES 256 (not tied to this algorithm but it seems to be a reasonable choice). These messages are usually very short at 128-256 bits. I'm ...
2
votes
1answer
170 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 ...
0
votes
1answer
76 views

How are TLSv1.0 ciphers negotiated as TLSv1.2?

I'm a little confused about something I am reading in Bulletproof SSL. "TLS 1.2 is the only protocol that allows suites to define their PRFs. This means that for the suites defined before TLS 1.2 ...