Officers are appealing for the man to come forward and to anyone who can help identify him to contact the police.
Detectives would like to speak to the man as he could have important information which could help the investigation.
To recap the incident, a 24-year-old woman was followed home from work at around 2.30am in the early hours of Sunday 26 October 2014.
As she walked along Nessgate and Walmgate a man followed her and spoke to her. When she entered the communal area of her home, she was attacked. She then screamed and her attacker ran off along Walmgate in the direction of the city walls.
Thankfully, the woman sustained only minor injuries during the assault.
Anyone who can help identify the man shown in the CCTV is asked to contact North Yorkshire Police on 101, select option 2 and ask for York CID. Or email yorkCID@northyorkshire.pnn.police.uk
If you wish to remain anonymous, you can pass information to Crimestoppers on 0800 555 111.
Please quote incident number 12140184683 when passing on information.