sha1

I have a doubt. I developed an Android App which receives push notifications via Google Cloud Messaging. Here are the steps I took: Creation of new Project on Google Developer console and copy/paste my Project Number in my android app. Registration of my App through RegID previously received by Google Cloud Messaging. Result: Ok! My App appears in database on my server. Copying/paste Api Key in my Server. I obtained my Api Key from Google Developer Console (Projcet/API/Credential/New API Key) creating new API Key without putting any SHA1 certificate. I exported my application (I use Android

G'day people, I am re-implementing an existent custom file upload service in ruby (sinatra) with redis as a backing store. Client calculates a SHA1 hash and initiates an upload uploads max 64K chunks until finished Server appends chunks to file calculates SHA1 hash of complete file to verify correct receipt Now, what I am hoping to do is use ruby (1.9.3) Digest::SHA1 << (update) operator on each chunk, (rather than having to read the ENTIRE file from scratch at the end). [Large files > 1GB]. Unfortunately Digest::SHA1 and Marshal.dump aren't compatible 1.9.3p125 :001 > require 'digest' => true

The MessageDigest class implements the SHA-1 algorithm (among many others). The SHA-1 algorithm allows one to use different "seeds" or initial digests. See SHA-1 Psuedocode The algorithm initializes variables, or the seed: Initialize variables: h0 = 0x67452301 h1 = 0xEFCDAB89 h2 = 0x98BADCFE h3 = 0x10325476 h4 = 0xC3D2E1F0 However the MessageDigest class, as described in the Online Java Manual , provides no API for setting these initial variables. In fact, it doesn't state the value of the initial variables. How can I set the initial seed for the SHA-1 algorithm? Where is an example of SHA-1

Just wondering if knowing the original string length means that you can better unlash a SHA1 encryption. No, not in the general case: a hash function is not an encryption function and it is not designed to be reversible. It is usually impossible to recover the original hash for certain. This is because the domain size of a hash function is larger than the range of the function. For SHA-1 the domain is unbounded but the range is 160bits. That means that, by the Pigeonhole principle , multiple values in the domain map to the same value in the range. When such two values map to the same hash, it

Can someone help me how can I easily use hash functions from Crypto++ library? I tried used these codes for SHA1 and MD5. I have many errors on line where is StringSink . The errors are like: undefined reference to `CryptoPP::StringSinkTemplate::StringSinkTemplate(std::string&)' Thanks for help. // SHA CryptoPP::SHA1 sha1; std::string source = "Hello"; std::string hash = ""; CryptoPP::StringSource(source, true, new CryptoPP::HashFilter(sha1, new CryptoPP::HexEncoder(new CryptoPP::StringSink(hash)))); std::cout << hash; // MD5 CryptoPP::MD5 hash; byte digest[ CryptoPP::MD5::DIGESTSIZE ]; std: