Correct misspellings.
diff --git a/Doc/lib/libhashlib.tex b/Doc/lib/libhashlib.tex
index 829849f..e9d0b57 100644
--- a/Doc/lib/libhashlib.tex
+++ b/Doc/lib/libhashlib.tex
@@ -15,7 +15,7 @@
message digest algorithms. Included are the FIPS secure hash algorithms SHA1,
SHA224, SHA256, SHA384, and SHA512 (defined in FIPS 180-2) as well as RSA's MD5
algorithm (defined in Internet \rfc{1321}).
-The terms secure hash and message digest are interchangable. Older
+The terms secure hash and message digest are interchangeable. Older
algorithms were called message digests. The modern term is secure hash.
\warning{Some algorithms have known hash collision weaknesses, see the FAQ at the end.}