} finally {
            this.signingLock.unlock();
        }
    }

    /**
     * Securely wipe signing key from memory
     */
    public void secureWipeKey() {
        this.signingLock.lock();
        try {
            if (this.signingKey != null) {
                java.util.Arrays.fill(this.signingKey, (byte) 0);
                this.signingKey = null;