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-rw-r--r--lib/hamming.go23
1 files changed, 23 insertions, 0 deletions
diff --git a/lib/hamming.go b/lib/hamming.go
index 1e53d54..05a7546 100644
--- a/lib/hamming.go
+++ b/lib/hamming.go
@@ -32,6 +32,29 @@ func setBits(b byte) int {
return int(c)
}
+
+// Returns key size with minimum normalized hamming distance
+// 'keyMin' is the minimum key size
+// 'keyMax' is the maximum key size
+func KeySizeWithMinDistance(keyMin, keyMax int) int {
+ var mk int = 0 // Key size with min distance.
+ var md float64 = 100.0 // Distance for key size 'mk'.
+ for k := keyMin; k <= keyMax; k++ {
+ p := genKey(k)
+ q := genKey(k)
+
+ // Compute distance.
+ d := HammingDistance(p, q)
+
+ nd := float64(d) / float64(k)
+ if nd < md {
+ mk = k
+ md = nd
+ }
+ }
+ return mk
+}
+
// Generates a key of size 'size' bytes.
func genKey(size int) []byte {
bs := make([]byte, size, size)