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Edited ch04.asciidoc with Atlas code editor

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nadams 2017-05-18 09:22:35 -07:00
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@ -64,7 +64,7 @@ More precisely, the private key can be any number between +1+ and +n - 1+, where
[WARNING]
====
((("warnings and cautions", "random number generation")))Do not write your own code to create a random number or use a "simple" random number generator offered by your programming language. Use a cryptographically secure pseudorandom number generator (CSPRNG) with a seed from a source of sufficient entropy. Study the documentation of the random number generator library you choose to make sure it is cryptographically secure. Correct implementation of the CSPRNG is critical to the security of the keys.
((("random numbers", "random number generation")))((("entropy", "random number generation")))Do not write your own code to create a random number or use a "simple" random number generator offered by your programming language. Use a cryptographically secure pseudorandom number generator (CSPRNG) with a seed from a source of sufficient entropy. Study the documentation of the random number generator library you choose to make sure it is cryptographically secure. Correct implementation of the CSPRNG is critical to the security of the keys.
====
The following is a randomly generated private key (k) shown in hexadecimal format (256 bits shown as 64 hexadecimal digits, each 4 bits):
@ -590,7 +590,7 @@ include::code/ec-math.py[]
[NOTE]
====
<<ec_math>> ((("random numbers", "os.urandom", see="entropy")))((("entropy", "os.urandom", see="random numbers")))((("warnings and cautions", "random number generation")))uses +os.urandom+, which reflects a cryptographically secure random number generator (CSRNG) provided by the underlying operating system. In the case of a Unix-like operating system such as Linux, it draws from +/dev/urandom+; and in the case of Windows, it calls +CryptGenRandom()+. If a suitable randomness source is not found, +NotImplementedError+ will be raised. While the random number generator used here is for demonstration purposes, it is _not_ appropriate for generating production-quality bitcoin keys as it is not implemented with sufficient security.((("", startref="KApython04")))
<<ec_math>> ((("random numbers", "os.urandom", see="entropy")))((("entropy", "os.urandom", see="random numbers")))((("random numbers", "random number generation")))((("entropy", "random number generation")))uses +os.urandom+, which reflects a cryptographically secure random number generator (CSRNG) provided by the underlying operating system. In the case of a Unix-like operating system such as Linux, it draws from +/dev/urandom+; and in the case of Windows, it calls +CryptGenRandom()+. If a suitable randomness source is not found, +NotImplementedError+ will be raised. While the random number generator used here is for demonstration purposes, it is _not_ appropriate for generating production-quality bitcoin keys as it is not implemented with sufficient security.((("", startref="KApython04")))
====
[[ec_math_run]]