src/org/kocakosm/pitaya/security/KDFs.java
public static KDF scrypt(int r, int n, int p, int dkLen)
	{
		return new SCrypt(r, n, p, dkLen);
	}
public static KDF scrypt(int r, int n, int p, int dkLen)
	{
		return new SCrypt(r, n, p, dkLen);
	}
Creates and returns a new immutable {@code KDF} instance implementing
the SCrypt algorithm (RFC 7914).

@param r the block size parameter.
@param n the CPU/Memory cost parameter.
@param p the parallelization parameter.
@param dkLen the desired length for derived keys, in bytes.

@return the created {@code KDF} instance.

@throws IllegalArgumentException if {@code r, dkLen} or {@code p} is
negative, or if {@code n} is not greater than 1 or if it is not
a power of 2 or if it is not less than 2 ^ (128 * r / 8), or if
{@code p} is greater than ((2 ^ 32 - 1) * 32) / (128 * r).