1 files changed, 3 insertions, 0 deletions

diff --git a/src/lib/libcrypto/bn/bn_mul.c b/src/lib/libcrypto/bn/bn_mul.c
index eb007e19e9..3e8baaad9a 100644
--- a/src/lib/libcrypto/bn/bn_mul.c
+++ b/src/lib/libcrypto/bn/bn_mul.c
@@ -61,6 +61,9 @@
 #include "bn_lcl.h"
 
 #ifdef BN_RECURSION
+/* Karatsuba recursive multiplication algorithm
+ * (cf. Knuth, The Art of Computer Programming, Vol. 2) */
+
 /* r is 2*n2 words in size,
  * a and b are both n2 words in size.
  * n2 must be a power of 2.