site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:cc:message-id:from:to :in-reply-to:content-type:content-transfer-encoding:mime-version :subject:date:references:x-mailer; bh=AyfbOrsn14kNwCHymwBFy8zZW9g7913MUEcOsWETWao=; b=A+2keBN1RuJ2TxrBMYOXwS1bF1zfJb3/HSHVnhUFa7DOrB9NM+QemL0VjAu7bOr2kN XL91Ex2Cp+gYo0Oo8ZOTi9AqAMDsiEsD/x3v7ZFwVQ9nM0dWxZIiCdpIRcE0mrlf9OlF Sexp+NfLabo456QM5MWuu8p3hzPQRSwpjBdt8= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=cc:message-id:from:to:in-reply-to:content-type :content-transfer-encoding:mime-version:subject:date:references :x-mailer; b=NaesM5xJWK84dyVaVZf3QoGSHdCO3hGUcUl3mbgCa98en8NA/ZrqI7haWso0t64Yf2 Qgj9sayhW9KdvX26IsokwgN4kaCq00DKDr0N29ttD9ELS3XX9ymCPlBs6v8cCLx5N/qq 8S1/BwrzZ0MmhVmfX2fjP0P4rSGdDu59ZWv8M= On Nov 25, 2009, at 11:56 AM, Terry Lambert wrote: Derek _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... Tour requirements sound like a sequence offset restarttable CSPRNG for use in a block cipher for use in whole device or file/block level encryption for a mass storage device. You will need to carry around your own CSPRNG code for this, as system supplied PRNGs are generally not CSPRNGs, and their implementation can (and does) change. Such things generally generate their nonce (the initial seed value) from a passphrase or cryptographically generated key block stored some place like a USB key fob. The way you are trying to go about this is very guessable and not at all secure; I merely need to feed in monotonically increasing integers until I get a matching output value, and then monotonically increase my input for each subsequent value in order to decode your ciphertext. A high school student could break your message in under an hour, and under 5 minimum if it were using in band metadata for structured contents (e.g. an RFC-822 email message). Ah - I should have specified that this application has nothing (at all) to do with cryptography. In case people are interested... this is an engineering simulation application. We just need to generate random input into it (but like I said... on a grand scale... and with the ability to both get the same numbers back at points.... AND change the numbers throughout the simulation at specific times). The strength of the random numbers matters little. Also... the portability doesn't matter... in that we're not worried about getting different numbers on different machines... as long as every machine spews numbers throughout the range we want. This email sent to site_archiver@lists.apple.com