diff --git a/openpgp-card-sequoia/src/card.rs b/openpgp-card-sequoia/src/card.rs
index f9c5cae..af48f31 100644
--- a/openpgp-card-sequoia/src/card.rs
+++ b/openpgp-card-sequoia/src/card.rs
@@ -349,6 +349,16 @@ impl<'a> Open<'a> {
         self.opt.algorithm_information()
     }
 
+    /// "MANAGE SECURITY ENVIRONMENT"
+    /// Make `key_ref` usable for the operation normally done by the key designated by `for_operation`
+    pub fn manage_security_environment(
+        &mut self,
+        for_operation: KeyType,
+        key_ref: KeyType,
+    ) -> Result<(), Error> {
+        self.opt.manage_security_environment(for_operation, key_ref)
+    }
+
     /// Get "Attestation Certificate (Yubico)"
     pub fn attestation_certificate(&mut self) -> Result<Vec<u8>, Error> {
         self.opt.attestation_certificate()
diff --git a/openpgp-card/src/apdu/commands.rs b/openpgp-card/src/apdu/commands.rs
index b50c193..fc05677 100644
--- a/openpgp-card/src/apdu/commands.rs
+++ b/openpgp-card/src/apdu/commands.rs
@@ -4,7 +4,7 @@
 //! Pre-defined `Command` values for the OpenPGP card application
 
 use crate::apdu::command::Command;
-use crate::{ShortTag, Tags};
+use crate::{KeyType, ShortTag, Tags};
 
 /// 7.2.1 SELECT
 /// (select the OpenPGP application on the card)
@@ -241,3 +241,19 @@ pub(crate) fn terminate_df() -> Command {
 pub(crate) fn activate_file() -> Command {
     Command::new(0x00, 0x44, 0x00, 0x00, vec![])
 }
+
+/// 7.2.18 MANAGE SECURITY ENVIRONMENT
+pub(crate) fn manage_security_environment(for_operation: KeyType, key_ref: KeyType) -> Command {
+    let p2 = match for_operation {
+        KeyType::Authentication => 0xA4,
+        KeyType::Decryption => 0xB8,
+        _ => unreachable!(), //FIXME
+    };
+    let data = match key_ref {
+        KeyType::Decryption => vec![0x83, 0x01, 0x02],
+        KeyType::Authentication => vec![0x83, 0x01, 0x03],
+        _ => unreachable!(),
+    };
+
+    Command::new(0, 0x22, 0x41, p2, data)
+}
diff --git a/openpgp-card/src/openpgp.rs b/openpgp-card/src/openpgp.rs
index f293703..d3026be 100644
--- a/openpgp-card/src/openpgp.rs
+++ b/openpgp-card/src/openpgp.rs
@@ -588,6 +588,40 @@ impl<'a> OpenPgpTransaction<'a> {
         Ok(resp.data().map(|d| d.to_vec())?)
     }
 
+    /// Set the key to be used for the pso_decipher and the internal_authenticate commands.
+    ///
+    /// Valid until next reset of of the card or the next call to `select`
+    /// The only keys that can be configured by this command are the `Decryption` and `Authentication` keys.
+    ///
+    /// The following first sets the *Authentication* key to be used for [pso_decipher](OpenPgpTransaction::pso_decipher)
+    /// and then sets the *Decryption* key to be used for [internal_authenticate](OpenPgpTransaction::internal_authenticate).
+    ///
+    /// ```no_run
+    /// # use openpgp_card::{KeyType, OpenPgpTransaction};
+    /// # let mut tx: OpenPgpTransaction<'static> = panic!();
+    /// tx.manage_security_environment(KeyType::Decryption, KeyType::Authentication)?;
+    /// tx.manage_security_environment(KeyType::Authentication, KeyType::Decryption)?;
+    /// # Result::<(), openpgp_card::Error>::Ok(())
+    /// ```
+    pub fn manage_security_environment(
+        &mut self,
+        for_operation: KeyType,
+        key_ref: KeyType,
+    ) -> Result<(), Error> {
+        log::info!("OpenPgpTransaction: manage_security_environment");
+
+        if !matches!(for_operation, KeyType::Authentication | KeyType::Decryption)
+            || !matches!(key_ref, KeyType::Authentication | KeyType::Decryption)
+        {
+            return Err(Error::UnsupportedAlgo("Only Decryption and Authentication keys can be manipulated by manage_security_environment".to_string()));
+        }
+
+        let cmd = commands::manage_security_environment(for_operation, key_ref);
+        let resp = apdu::send_command(self.tx(), cmd, false)?;
+        resp.check_ok()?;
+        Ok(())
+    }
+
     // --- sign ---
 
     /// Sign `hash`, on the card.