diff --git a/irma/cmd/prolong.go b/irma/cmd/prolong.go
new file mode 100644
index 00000000..fbc77bc3
--- /dev/null
+++ b/irma/cmd/prolong.go
@@ -0,0 +1,183 @@
+package cmd
+
+import (
+	"fmt"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"os"
+
+	"github.com/privacybydesign/irmago/internal/common"
+	"github.com/spf13/cobra"
+)
+
+var prolongCmd = &cobra.Command{
+	Use:   "prolong [<path>] [<timestamp>]",
+	Short: "Prolong expiring public and private keys so they are at least valid until the specified timestamp",
+	Long:  "The prolong command updates the latest public and private keys for non deprecated issuers by setting <ExpiryDate> to the specified timestamp for keys which expire before that timestamp.\n\n",
+	Run: func(cmd *cobra.Command, args []string) {
+
+		if len(args) < 2 {
+			die("Invalid arguments given", nil)
+		}
+
+		path := args[0]
+		exists, err := common.PathExists(path)
+		if err != nil || !exists {
+			die("Could not check path existence", err)
+		}
+
+		timestamp, err := strconv.ParseInt(args[1], 10, 64)
+		if err != nil {
+			die("Invalid timestamp", err)
+		}
+
+		keys, err := findHighestKeys(path)
+		if err != nil {
+			die("Could not find keys", err)
+		}
+
+		for _, key := range keys {
+
+			// Is this key part of a deprecated issuer?
+			deprecated, err := deprecated(key, timestamp)
+
+			if err != nil {
+				die("Could not check if key is deprecated", err)
+			}
+
+			if !deprecated {
+				updateExpiryDate(key, timestamp)
+			} else {
+				fmt.Printf("Skipping deprecated key: %s\n", key)
+			}
+		}
+	},
+}
+
+func findHighestKeys(path string) ([]string, error) {
+	var keys []string
+
+	if err := filepath.Walk(path, func(path string, file os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if !file.IsDir() {
+
+			// Is this a key?
+			if r, err := regexp.MatchString("[0-999].xml", file.Name()); err != nil || !r {
+				return err
+			}
+
+			// Get the key number to be able to determine if there is a higher key number available
+			keyNr, err := strconv.ParseInt(strings.Split(file.Name(), ".")[0], 10, 64)
+			if err != nil {
+				return err
+			}
+
+			nextKey := filepath.Dir(path) + "/" + strconv.FormatInt(keyNr+1, 10) + ".xml"
+			exists, err := common.PathExists(nextKey)
+			if err != nil || exists {
+				// There is a higher key number available in the same folder so we skip this one
+				return err
+			}
+
+			absPath, err := filepath.Abs(path)
+			if err != nil {
+				return err
+			}
+
+			keys = append(keys, absPath)
+		}
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+
+	return keys, nil
+}
+
+// Is this key part of a deprecated issuer?
+func deprecated(file string, timestamp int64) (bool, error) {
+
+	descriptionFile := filepath.Dir(file) + "/../description.xml"
+
+	foundTimestamp, err := findTimestamp(descriptionFile, "(<DeprecatedSince>)(.*?)(</DeprecatedSince>)")
+	if err != nil {
+		return false, err
+	}
+
+	if foundTimestamp == 0 || foundTimestamp >= timestamp {
+		// Is not deprecated or does not become deprecated before given timestamp
+		return false, nil
+	}
+
+	return true, nil
+}
+
+func updateExpiryDate(file string, timestamp int64) error {
+	foundTimestamp, err := findTimestamp(file, "(<ExpiryDate>)(.*?)(</ExpiryDate>)")
+	if err != nil {
+		return err
+	}
+
+	if foundTimestamp >= timestamp {
+		// Does not expire before given timestamp
+		return nil
+	}
+
+	if err := replaceTimestamp(file,
+		"<ExpiryDate>"+strconv.FormatInt(foundTimestamp, 10)+"</ExpiryDate>",
+		"<ExpiryDate>"+strconv.FormatInt(timestamp, 10)+"</ExpiryDate>"); err != nil {
+		return err
+	}
+
+	fmt.Printf("Prolonged key: %s\n", file)
+
+	return nil
+}
+
+func replaceTimestamp(file string, find string, replace string) error {
+	bytes, err := os.ReadFile(file)
+	if err != nil {
+		return err
+	}
+
+	result := strings.ReplaceAll(string(bytes), find, replace)
+
+	if err := os.WriteFile(file, []byte(result), 0644); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func findTimestamp(file string, pattern string) (int64, error) {
+	bytes, err := os.ReadFile(file)
+	if err != nil {
+		return 0, err
+	}
+
+	regex, err := regexp.Compile(pattern)
+	if err != nil {
+		return 0, err
+	}
+
+	matches := regex.FindSubmatch(bytes)
+	if len(matches) == 0 {
+		return 0, nil
+	}
+
+	timestamp, err := strconv.ParseInt(string(matches[2]), 10, 64)
+	if err != nil {
+		return 0, err
+	}
+	return timestamp, nil
+}
+
+func init() {
+	schemeCmd.AddCommand(prolongCmd)
+}