diff --git a/cmd/taler-auditor-offline-signing/main.go b/cmd/taler-auditor-offline-signing/main.go
index c997165..f9050e1 100644
--- a/cmd/taler-auditor-offline-signing/main.go
+++ b/cmd/taler-auditor-offline-signing/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"crypto/rsa"
+	"encoding/base32"
 	"encoding/binary"
 	"fmt"
 	"math/big"
@@ -48,20 +49,28 @@ type EdDSASignature struct {
 	S [256 / 8]byte `json:"s"`
 }
 
-// following gnunet/src/util/crypto_rsa.c
+// following gnunet/src/json/json_helper.c and gnunet/src/util/crypto_rsa.c
 func (ep *EncodedRSAPublicKey) Decode() (p rsa.PublicKey, e error) {
-	buf := []byte(*ep)
+	var buf []byte
+
+	// 1. decode base32
+	_, e = base32.StdEncoding.Decode(buf, *ep)
+	if e != nil {
+		return
+	}
+
+	// 2. parse header
 	if len(buf) < 4 {
 		e = fmt.Errorf("byte array too small for RSA public key header")
 		return
 	}
-
 	modulus_length, public_exponent_length := binary.BigEndian.Uint16(buf[0:]), binary.BigEndian.Uint16(buf[2:])
 	if len(buf[4:]) != int(modulus_length)+int(public_exponent_length) {
 		e = fmt.Errorf("byte array has wrong size according to encoded length's for modulus and public exponent")
 		return
 	}
 
+	// 3. parse RSA public key
 	// BUG! This is most likely wrong.
 	// Consult _gcry_mpi_set_buffer from libgcrypt-1.9.4/mpi/mpicoder.c
 	buf = buf[4:]