README.md: linkify random blinding (#379)

README.md

@@ -73,7 +73,7 @@ only one minor finding which has since been addressed.
 See the [open security issues] on our issue tracker for other known problems.
 
 Notably the implementation of [modular exponentiation is not constant time],
-but timing variability is masked using random blinding, a commonly used
+but timing variability is masked using [random blinding], a commonly used
 technique.
 
 ## Minimum Supported Rust Version (MSRV)
@@ -117,3 +117,4 @@ dual licensed as above, without any additional terms or conditions.
 [audit]: https://www.opentech.fund/results/security-safety-audits/deltachat/
 [open security issues]: https://github.com/RustCrypto/RSA/issues?q=is%3Aissue+is%3Aopen+label%3Asecurity
 [modular exponentiation is not constant time]: https://github.com/RustCrypto/RSA/issues/19
+[random blinding]: https://en.wikipedia.org/wiki/Blinding_(cryptography)