diff --git a/crypto/NBuild.build b/crypto/NBuild.build
index d6cd1a170b..8eed0bec13 100644
--- a/crypto/NBuild.build
+++ b/crypto/NBuild.build
@@ -16,7 +16,7 @@
   <property name="dist-path" value="./dist"/>
 
   <!-- Version -->
-  <property name="version" value="1.8.10"/>
+  <property name="version" value="1.9.0"/>
   <property name="name" value="BouncyCastle.Crypto"/>
 
   <property name="OPTIONAL_STRONG_NAME" value="" />
diff --git a/crypto/Readme.html b/crypto/Readme.html
index cd117ca643..ac9efdb33a 100644
--- a/crypto/Readme.html
+++ b/crypto/Readme.html
@@ -30,6 +30,8 @@ <h3><a class="mozTocH3" name="mozTocId685176"></a>Contents:<br/></h3>
 			<li>
 				<a href="#mozTocId3413">Notes:</a>
 		<ol>
+            <li>
+                <a href="#mozTocId85325">Release 1.9.0</a>
             <li>
                 <a href="#mozTocId85324">Release 1.8.10</a>
             <li>
@@ -308,6 +310,32 @@ <h3><a class="mozTocH3" name="mozTocId358608"></a>For first time users.</h3>
 		<hr style="WIDTH: 100%; HEIGHT: 2px">
 		<h3><a class="mozTocH3" name="mozTocId3413"></a>Notes:</h3>
 
+        <h4><a class="mozTocH4" name="mozTocId85325"></a>Release 1.9.0, Sunday October 17, 2021</h4>
+
+        <h5>Defects Fixed</h5>
+        <ul>
+            <li>Key sizes are now checked strictly in TwofishEngine.</li>
+            <li>Fixed bzip2 compression of empty contents.</li>
+            <li>Handle CRL with no NextUpdate properly during CertPath validation.</li>
+            <li>Skip marker packets when reading various PGP data.</li>
+            <li>Ignore PGP signatures with invalid version.</li>
+        </ul>
+        <h5>Additional Features and Functionality</h5>
+        <ul>
+            <li>A new TLS API (Org.BouncyCastle.Tls) now replaces the old one (Org.BouncyCastle.Crypto.Tls), which
+            should be considered obsolete. The new API includes support for TLS 1.3.</li>
+            <li>Added support for Format Preserving Encryption.</li>
+            <li>Added support for ParallelHash and TupleHash.</li>
+            <li>Added support for the ARIA cipher.</li>
+        </ul>
+        <h5>Additional Notes</h5>
+        <ul>
+            <li>
+                See the (cumulative) list of GitHub pull requests that we have accepted at
+                <a href="https://github.com/bcgit/bc-csharp/pulls?q=is%3Apr+is%3Aclosed">bcgit/bc-csharp</a>.
+            </li>
+        </ul>
+
         <h4><a class="mozTocH4" name="mozTocId85324"></a>Release 1.8.10, Tuesday February 16, 2021</h4>
 
         <h5>Defects Fixed</h5>
diff --git a/crypto/src/AssemblyInfo.cs b/crypto/src/AssemblyInfo.cs
index f7c2f0e3dd..ec06092a09 100644
--- a/crypto/src/AssemblyInfo.cs
+++ b/crypto/src/AssemblyInfo.cs
@@ -33,9 +33,9 @@
 // You can specify all the values or you can default the Revision and Build Numbers
 // by using the '*' as shown below:
 
-[assembly: AssemblyVersion("1.8.10.0")]
-[assembly: AssemblyFileVersion("1.8.21047.1")]
-[assembly: AssemblyInformationalVersion("1.8.10")]
+[assembly: AssemblyVersion("1.9.0.0")]
+[assembly: AssemblyFileVersion("1.9.21290.1")]
+[assembly: AssemblyInformationalVersion("1.9.0")]
 
 //
 // In order to sign your assembly you must specify a key to use. Refer to the