Small speedup by using >>> in the _encipher() loop which allows us to remove two & 0xFF instructions. This saves ~30ms on my machine (at cost 12).

Author: Adam B

src/bcrypt/impl.js

@@ -277,13 +277,13 @@ function _encipher(lr, off, P, S) { // This is our bottleneck: 1714/1905 ticks /
     l ^= P[0];
     for (var i=0, k=BLOWFISH_NUM_ROUNDS-2; i<=k;)
         // Feistel substitution on left word
-        n  = S[(l >> 24) & 0xff],
+        n  = S[l >>> 24],
         n += S[0x100 | ((l >> 16) & 0xff)],
         n ^= S[0x200 | ((l >> 8) & 0xff)],
         n += S[0x300 | (l & 0xff)],
         r ^= n ^ P[++i],
         // Feistel substitution on right word
-        n  = S[(r >> 24) & 0xff],
+        n  = S[r >>> 24],
         n += S[0x100 | ((r >> 16) & 0xff)],
         n ^= S[0x200 | ((r >> 8) & 0xff)],
         n += S[0x300 | (r & 0xff)],