code: func (k *IdentityKey) PubString() string {
  	buf := new(bytes.Buffer)
  	buf.Write(idPubPrefix)
  	buf.Write(k.PubBytes())
  
  	check := shad(buf.Bytes())[:ChecksumLength]
  	buf.Write(check)
  
  	return base58.Encode(buf.Bytes())
  }
docs: // PubString returns the string encoding of the public key