a method for constructing a message authentication code based on a cryptographic hash function.

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7
votes
1answer
129 views

How the AWS signature works in depth

I'm trying to understand how the AWS signature 4 works. I read the docs and I found a Python example where a signature is computed. I also ran into this answer which explains HMAC a bit. I'm curious ...
2
votes
1answer
107 views

Does using the same secret key for AES-256-CBC and HMAC-SHA512 in Encrypt-then-MAC potentially compromise the key?

Suppose I use a key (and IV) to encrypt a piece of binary data with AES-256-CBC to produce the corresponding encrypted data. Suppose I then throw this encrypted data into HMAC-SHA512 using the same ...
1
vote
1answer
1k views

What is a AUTH-KEY in the security of the computers?

I'm studying security in computers and in particular the URL Spoofing. I understand that a form of URL spoofing is phishing. Then I read that a countermeasure against phishing is the authentication ...
5
votes
0answers
181 views

Secure backup encryption with OpenSSL

I know, the general advice is "keep your hands off crypto stuff". And the standard way to encrypt backup data securely would be using GnuPG. However, for a rather academic exercise, I would like to ...
3
votes
0answers
56 views

Why isn't Amazon using a NONCE for REST Authentication?

When you look at Amazons RESTAuthentication you can see that it doesn't use a nonce: Authorization = "AWS" + " " + AWSAccessKeyId + ":" + Signature; Signature = Base64( HMAC-SHA1( ...
3
votes
0answers
40 views

how to create TPM_AUTHDATA as input in tpm commands ?

I'm writing my first program which use tpm (version 1.2) services in Windows 7 using TBS, in this program I'm trying to execute the TPM_CreateWrapKey command. I noticed that many commands like the ...
2
votes
0answers
65 views

cracking krb5 passwords (des3-hmac-sha1 and des-cbc-crc )

I'm trying to audit kerberos passwords. The available formats are des3-hmac-sha1 and des-cbc-crc but I cannot find a possibility/a tool to crack them. For other hash-types I used John the Ripper, but ...
2
votes
0answers
108 views

Securing a JavaScript app with RESTful backend

I went through the question Securing a JavaScript Single Page App with RESTful backend that has discussions / options around securing a Javascript client side app that invokes RESTful APIs. However, ...
2
votes
0answers
177 views

Allowing third-party clients to authenticate with an app server

I'm working on an app that is planned to be licensed to OEMs, who would in turn offer it as a service to their users.  We would host the app server and the OEM would optionally host the app's web ...
2
votes
0answers
240 views

Is hashing the HMAC secret key a good idea?

I'm implementing a REST API and I've generated 128-bit random API keys which are used with HMAC-SHA1 for authorization. Should I hash the secret key on both the client and server before using it, ...
1
vote
0answers
13 views

Is my current implementation of message signing on AVR sufficient and correct?

I am currently implementing a fairly simple signing library (for my personal use) to verify the identity of packets sent with the RF24Mesh library (using NRF24L01+) radios. Never made a flowchart but ...
1
vote
0answers
75 views

Securing ASP.net web api (REST)

I am developing a middle-ware web service app(REST) using asp.net mvc-4 web api. The rest services are consumed by android,ios,angularjs client apps.Same user is able to use multiple platforms at the ...
1
vote
0answers
98 views

How can I use session salt for encrypting data using AES in CTR mode?

I have to implement a crypto-plugin in Java. The approach followed is conceptually similar to that used for SRTP. The algorithm used for data confidentiality is AES in CTR mode (I'm following a ...
1
vote
0answers
186 views

HMAC authenticated API calls with multipart/form-data file uploads

We have an existing API where 3rd parties can push data. The API calls are authenticated with HMAC using the same scheme as described in Ruby's ApiAuth library which I use to verify signed requests. ...
1
vote
0answers
226 views

Login Authentication with SSL and HMAC

My question is pretty similar to : http://stackoverflow.com/questions/5487757/using-hmac-sha1-for-api-authentication-how-to-store-the-client-password-secure. Basically, I want to write an API for my ...
1
vote
0answers
264 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
2k views

Want to implement a really good authentication mechanism for REST API

I own a web application (single page application with Angular), that asks for some data through a set of REST APIs based on my server-side application (using Play Framework 2.2.1). So basically, I'm ...
1
vote
0answers
447 views

Generating API keys within an OAuth2 session for non-web-browser clients

I am using Google's OAuth2 for authentication for a website which also has a RESTful API component. I would like to support connections from clients which are not within a web browser. Also, I'd ...
0
votes
0answers
107 views

Data integrity and authentication of an Arduino using JSON Web Tokens and HMACs

I have a school project involving an Arduino-based sensor that needs to send sensor readings to a server via HTTP. The sensor readings do not need to be encrypted (it's okay that people know what they ...
0
votes
0answers
50 views

SQLCipher and PRAGMA key on iOS

I'm a bit confused as to how SQLCipher handles the PRAGMA key provided for encrypting the SQLite database For background: I'm looking at options for encrypting application data at rest. From the ...
0
votes
0answers
142 views

HMAC Token - Check Logic

I have a situation where I need a token that provides authentication. The common HMAC procedure I found is: Get Some key using login credentials Create Message, append key and other message data (...
0
votes
0answers
11 views

What integrity does the TLS Record Protocol actually provide?

In TLS the "base" protocol is the "TLS Resource Protocol". This protocol is responsible for: securing application data and verifying its integrity and origin. It also uses a HMAC. However this ...
0
votes
0answers
153 views

C# app and ASP.NET api: validating requests/responses

So I have one C# WPF desktop app (client), which communicates with my web api to login for the user, get info, etc. The C# WPF app will communicate with a hardware device as well. However, there is a ...
0
votes
0answers
51 views

Data Model for a Tokenizing Data Storage System

Hashing Strategy for a Tokenizing Data Storage System We are designing the data model (storage at rest, in a database) for a PCI compliant data storage system using Amazon Web Services (AWS) and ...
0
votes
0answers
82 views

Understanding the application of hashes, HMACs, and KDFs

I think that I understand the right application cases for the following crypto functions, but I'd like to confirm my understanding and also propagate the safe use of crypto throughout the intertubes. ...
0
votes
0answers
87 views

Using HMAC when sending data through an untrusted server

I have a set up like this: Payment Server (PS) <> Front End (FE) <> Client JS. I need to get some data from the Client JS to the PS, without the FE being able to modify it and have PS prove ...
0
votes
0answers
138 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 ...