diff --git a/build.gradle b/build.gradle
index bbe4564f5f..abcdae890e 100644
--- a/build.gradle
+++ b/build.gradle
@@ -113,7 +113,7 @@ subprojects {
 
     version = '5.2.0-SNAPSHOT'
     ext {
-        bouncyCastleVersion = '1.69'
+        bouncyCastleVersion = '1.70'
         commonsCodecVersion = '1.15'
         commonsCompressVersion = '1.21'
         commonsIoVersion = '2.11.0'
diff --git a/build.xml b/build.xml
index de89217ecc..0a339f0968 100644
--- a/build.xml
+++ b/build.xml
@@ -296,11 +296,11 @@ under the License.
 
     <!-- xml signature libs - not part of the distribution -->
     <dependency prefix="dsig.xmlsec" artifact="org.apache.santuario:xmlsec:2.3.0" usage="ooxml-provided"/>
-    <dependency prefix="dsig.bouncycastle-prov" artifact="org.bouncycastle:bcprov-jdk15on:1.69" usage="ooxml-provided"/>
-    <dependency prefix="dsig.bouncycastle-pkix" artifact="org.bouncycastle:bcpkix-jdk15on:1.69" usage="ooxml-provided"/>
-    <dependency prefix="dsig.bouncycastle-util" artifact="org.bouncycastle:bcutil-jdk15on:1.69" usage="ooxml-provided"/>
+    <dependency prefix="dsig.bouncycastle-prov" artifact="org.bouncycastle:bcprov-jdk15on:1.70" usage="ooxml-provided"/>
+    <dependency prefix="dsig.bouncycastle-pkix" artifact="org.bouncycastle:bcpkix-jdk15on:1.70" usage="ooxml-provided"/>
+    <dependency prefix="dsig.bouncycastle-util" artifact="org.bouncycastle:bcutil-jdk15on:1.70" usage="ooxml-provided"/>
     <!-- only used for signing the release - not used with the ooxml signatures -->
-    <dependency prefix="dsig.bouncycastle-bcpg" artifact="org.bouncycastle:bcpg-jdk15on:1.69" usage="util"/>
+    <dependency prefix="dsig.bouncycastle-bcpg" artifact="org.bouncycastle:bcpg-jdk15on:1.70" usage="util"/>
 
     <!-- svg/batik/pdf libs - not part of the distribution - move batik to its own directory because of JPMS module-path issues -->
     <dependency prefix="svg.xml-apis-ext" artifact="xml-apis:xml-apis-ext:1.3.04" usage="ooxml-batik"/>
diff --git a/osgi/README.md b/osgi/README.md
index d5f6791205..891607b583 100644
--- a/osgi/README.md
+++ b/osgi/README.md
@@ -29,7 +29,7 @@ These are required to sign or validate signed Office documents. The OSGi bundles
     
     - XML Commons Resolver: https://mvnrepository.com/artifact/xml-resolver/xml-resolver/1.2-osgi
     
-    - Bouncy Castle: https://mvnrepository.com/artifact/org.bouncycastle/bcprov-ext-jdk15on/1.69, https://mvnrepository.com/artifact/org.bouncycastle/bcpkix-jdk15on/1.69
+    - Bouncy Castle: https://mvnrepository.com/artifact/org.bouncycastle/bcprov-ext-jdk15on/1.70, https://mvnrepository.com/artifact/org.bouncycastle/bcpkix-jdk15on/1.70
 4. PDFBox and PDFBox Graphics2D  
 Required to render to PDF documents.
 The required jars can be downloaded from: