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To create private key, we retry when the random number is less than n - 1; even if it is n - 1; Issue #28

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Minh T. Nguyen 2014-05-25 17:23:47 -07:00
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@ -40,7 +40,7 @@ A +private key+ is simply a number, picked at random. Ownership and control over
===== Generating a private key from a random number
A private key is a number between +1+ and +n - 1+, where n is a constant defined in the elliptic curve standard (latexmath:[\(n = 1.158 * 10^\(77\) \)], n is the order of the elliptic curve used in bitcoin. See <<elliptic_curve>>). To create such a key, we randomly pick a 256-bit number and check that it is less than +n - 1+. In programming terms, this is usually achieved by feeding a larger string of random bits, collected from a cryptographically-secure source of randomness, into the SHA-256 hash algorithm which will conveniently produce a 256-bit number. If the result is less than +n - 1+, we have a suitable private key. If it is greater than +n - 1+, we simply try again with another random number.
A private key is a number between +1+ and +n - 1+, where n is a constant defined in the elliptic curve standard (latexmath:[\(n = 1.158 * 10^\(77\) \)], n is the order of the elliptic curve used in bitcoin. See <<elliptic_curve>>). To create such a key, we randomly pick a 256-bit number and check that it is less than +n - 1+. In programming terms, this is usually achieved by feeding a larger string of random bits, collected from a cryptographically-secure source of randomness, into the SHA-256 hash algorithm which will conveniently produce a 256-bit number. If the result is less than +n - 1+, we have a suitable private key. Otherwise, we simply try again with another random number.
[TIP]
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