In terms of identifying the calligrapher, the most prominent theory is that he was FUJIWARA no Yukitsune (1012-1050, also known as Yukitsune SESONJI), son of famed calligrapher FUJIWARA no Yukinari (his first name can also be rendered as Kozei), but there is no definitive proof of this.
筆者については藤原行成の子の世尊寺行経（1012-1050）とする説が有力だが、確証はない。