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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2answers
74 views

Can the intended recipient be derived from a public-key encrypted ciphertext?

Assuming you have a list of possible recipients' public keys, and a ciphertext encrypted with one of those public keys, would it be possible to determine which public key?
3
votes
2answers
178 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 ...
2
votes
2answers
187 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 ...
2
votes
2answers
160 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 ...
0
votes
2answers
185 views

Untraceable Digital Cash?

I have read some articles regarding digital cash that is untraceable (Here). Their protocol is provided below Withdrawal: Alice creates an electronic coin and blinds it. Alice sends the ...
0
votes
2answers
209 views

Asymmetric vs Symmetric Encryption Benchmarks

I have found these benchmarks in Crypto++'s site. http://www.cryptopp.com/benchmarks.html But I am, quite honestly, not entirely sure how to interpret them. I am really looking for a set of ...
19
votes
1answer
505 views

How to encrypt in PHP, properly?

How do I encrypt data in PHP, properly, using symmetric-key encryption? I have a message M and a secret S. I'm looking for a solution that uses cryptography properly without making any of the usual ...
2
votes
1answer
312 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 ...
2
votes
1answer
329 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 ...
1
vote
1answer
66 views

Is HTML5 sessionStorage secure for temporarily storing a cryptographic key?

Assume I am building a local web application (e.g. browser extension) in HTML5 to encrypt a database locally. Access to the database is controlled by a password and a cryptographic master key is ...
1
vote
1answer
124 views

Need help designing an encryption workflow

Background: I'm building a .NET application, a very small part of this application allows for users to communicate with a third party application. I am designing this aspect. The third party simply ...
0
votes
1answer
107 views

Prevent CryptoLocker on Server

A quick question, which may have a not-so-quick answer - Are there any ways to prevent files associated with CryptoLocker, to be propagated to a data server, by means of a back up? We use Cobian as ...
0
votes
1answer
123 views

Is it dangerous to use the same key (RSA) for both encryption (PGP) and authentication (SSH)?

Alice wants to send an encrypted message to Bob, but she also wants to connect to Carol's server. Are there any dangers associated with using the same RSA key for both PGP and SSH (other than a lack ...
0
votes
1answer
46 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 ...
0
votes
1answer
126 views

Can you recover the password from ZipCrypto encrypted ZIP file?

I know that "legacy ZIP-crypto" is not secure and you can get at the contents of the file quite easily. Now the question is, can you also get at the password (assume this is a very long, very high ...
0
votes
1answer
155 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 ...
-1
votes
1answer
109 views

What encryption algorithm does CryptEncrypt in Crypto API use?

I am writing a code to perform encryption and decryption using CryptEncrypt and CryptDecrypt functions, a part of Windows' Crypto API. Can anyone tell me what kind of encryption these two function ...
-1
votes
1answer
30 views

combining imperfect random number generators for shuffling an array

Shuffling an array to create a random stream for encryption is well known. The weakness is in the security of the random number generator that performs the shuffling. But is it true or likely that the ...
2
votes
0answers
43 views

How does SHA3 (Keccak & SHAKE) compare to SHA2? Should I use non-SHAKE parameters?

Keccak is the winner of the SHA3 competition. Since Keccak is highly customizable (presumably for security/memory/time/speed tradeoffs) there does seem to be some controversy around how Keccak ...
2
votes
0answers
27 views

Reference Implementation for Shoup's ECIES?

ECIES is part of both ISO/IEC and IEEE. There's a interop bug between Crypto++'s ECIES and Bouncy Castle's ECIES. I know where the bug lies, and I've been trying to determine who is "right" (for some ...
2
votes
0answers
58 views

Offering a privacy scenario with PHP mcrypt library

first of all, sorry if my question is not clear, because English is not my first language. Anyway, let-me explain the concept I'm struggling to solve as the best solution. I have some guys, and they ...
2
votes
0answers
102 views

Which keys does a bank typically exchange with a card scheme?

I'm trying to understand the different EMV-related keys that are shared between a bank who issues EMV cards and a card scheme, such as Visa or MasterCard. I understand the bank would typically ...
2
votes
0answers
104 views

Main difference between Yahalom and Needham-Schroeder key exchange protocols

I am just wondering what is the main difference between the Yahalom and Needham-Schroeder key exchange protocols? Which protocol uses less computational power?
2
votes
0answers
61 views

What flexibility does a “Third party gamma” offer to U-Prove deployment?

The U-Prove SDK has the following comment: (link) // 1: CA-RA split (a party trusted by the issuer provides the gamma value) Given that the Gamma value (if provided) overrides the Attributes value, ...
2
votes
0answers
94 views

In U-Prove, what is the purpose of “Pseudonyms”, “Committed”, and “Scope” values and how are they used?

U-Prove allows for anonymous authentication and authorization without the involvement of an IdP. When a client generates a presentation proof 3 values can be optionally included, but I can't find ...
1
vote
0answers
73 views

Questions about SRP algorithm

I trying to use SRP algorithm but I have some questions: Is that a good choice to use for registration and authorization SRP algorithm with SSL/TLS? And for all other transmission using just ...
1
vote
0answers
76 views

Problem in understanding Blakley's Secret Sharing Scheme

I need to implement Blakley's Secret Sharing Scheme. I have read below mentioned two research papers but still unable to understand how to implement it. 1. Safeguarding cryptographic keys 2. Two ...
1
vote
0answers
53 views

Public keys Quality

Is there any way to test the quality of generated keys from a public key cryptosystem? I've read about the common RSA attacks, but attacking the algorithm may not mean checking if the generated keys ...
1
vote
0answers
31 views

Key management for hosting applications

We're looking to host a number of client applications in our environment. Some of those will use crypto, e.g. for ssl or database encryption and obviously we'll need to manage keys for that. I am ...
1
vote
0answers
185 views

RSA 4096 key size difference - “sig” and “sig 3”

Whenever I generate a new 4096 RSA key in my GPG program and export the public key to a text file, I get a text file containing a total of around 52 lines (it varies, one of them is 53 lines). ...
1
vote
0answers
38 views

DTLS CertificateVerify doubt

In DTLS 1.2 RFC 6347, section 4.2.6: CertificateVerify and Finished messages have the same format as in TLS. Hash calculations include entire handshake messages, including DTLS-specific fields: ...
1
vote
0answers
687 views

OpenSSL: Bad Record MAC on TLS Heart Beat

I am trying to see the heartbleed bug in action with my OpenSSL server application. My server uses the OpenSSL library - openssl-1.0.1b I successfully connect with s_client (openssl-1.0.1b) to my ...
1
vote
0answers
165 views

Storing private messages in a database

I am creating a portal where users can send private messages (PMs) for a very large audience. So I want to encrypt the messages and store them in the database. But I do not want to ask the users for ...
1
vote
0answers
955 views

Brute-Force/Dictionary attack against encypted file using PBKDF2 key derivation

I have been following this very useful post by Thomas. My use case is slightly different. I am developing a mobile application which requires some sensitive data to be stored on the device in a SQLite ...
1
vote
0answers
159 views

Gladman's file encryption library = AES in counter mode with HMAC-SHA1 authentication?

I would like to use Gladman's algorithm to create AES encrypted data in JavaScript. I use the Crypto-JS library, but its performance is horrible. PBKDF2 is terribly slow, so I switched to another ...
1
vote
0answers
51 views

Is it possible to produce incorrect Metadata?

There is an app on xposed installer called XPrivacy for android that let's you decide what information you want your device to give a specific app and for information you don't want to give it ...
1
vote
0answers
113 views

Putty Event Log

Can anyone explain me the Step by step process of Key Exchange that takes place while accessing Linux machine using Putty ? I found the Event Log of Putty but the Various Key Exchange didn't make very ...
1
vote
0answers
59 views

Any Suggestion Exchanging shared key between process via port in untrusted machine (infected my malware)?

I am trying to get shared key between Firefox extension and a java program running in same machine. I am communicating both application via socket. My assumption is that malware is running in ...
1
vote
0answers
335 views

Configure Asterisk for lan with SRTP enabled SipDroid

I want to have a secured call over internet between two android phones. I have found SipDroid which is an open source SIP client for Android. And also I have followed this to install Asterisk, Dahdi ...
0
votes
0answers
40 views

Designing a security system for road pricing

It's my first semester with Information Security and I still feel a little lost. Sorry in advance for stupid mistakes I may have made. the examples in round brackets below are my own ideas, wrote ...
0
votes
0answers
27 views

TLS fallback when only one protocol is enabled

Consider I have IE with ONLY TLS 1.2 enabled. TLS 1.0 and 1.1 are disabled. (And SSLv2,v3) I have a server that only supports TLS1.2, with 1.0 and 1.1 disabled as well. Assuming they share a ...
0
votes
0answers
84 views

Cryptographic Testing

Given an algorithm (say, AES), how to create/generate test vectors? I have tried using the NIST test vectors for AES and found it to be working fine with a package of "chilkat". Suppose, for a ...
0
votes
0answers
124 views

Client authentication with a collection of open source distributed servers

With a collection of open source distributed servers, all sharing every users data. How can the user authenticate with any server, without the passwords being compromised by a malicious server? ...
0
votes
0answers
60 views

Suggestion of encrypt method for short fixed size result

I'm searching for a encrypt method that receives an int variable and outputs exactly 11 hexadecimal digits. I'm starting on a existing application, that already has a database of more than 130.000 ...
0
votes
0answers
23 views

Infer encoding mechanism from n-grams distance

I have a series of obfuscated strings which across the set of strings have regions of high variance and regions of low variance (implying some encoding mechanism as opposed to an encryption procedure ...
0
votes
0answers
84 views

How does Spideroak manage encryption keys

I'm trying to understand the following from SpiderOak's engineering page (sorry I'm on a mobile phone so have no access to formatting functions like quote blocks): "SpiderOak uses a nested series of ...
0
votes
0answers
97 views

Public/Private key validation

Suppose I have this scenario: User --> Inputs License Key --> I validate it --> If success, good, move onto main window. If not, prompt the user to reenter the license key. The license key will not ...
0
votes
0answers
79 views

Payment Application Integration - Encryption or HMAC

Doing an integration with an online payment provider. Payment provider will be making a web request to my server to provide some information about the basket content. On my end there's no payment ...
0
votes
0answers
47 views

Mobile App Processing Debit Card Transactions

I am creating a mobile app for iPhone and Android and the respective API that will be exposed to support the operations. This operations will require the customer to type the PIN to complete the ...