Technically, a timestamp is an electronic signature that guarantees the existence of the cryptographic digest of a document at a certain point in time. Therefore, its validity is subject to the validity of the certificate that produces it.

The AOC Consortium has a policy of annual renewal of the certificates used to sign the time stamps we issue, in order to guarantee that they will be valid for a minimum of three years.
The following table shows the dates of issue, expiry and start-up of the different time stamp certificates used by CATCert and the AOC Consortium since the start of the provision of the service:

Year Issue expiry Installation at the TSA Certificate
2006 31/03/2006 31/03/2010
2009 08/03/2009 03/08/2013 15/10/2009 B9E59E25.zip
2011 03/10/2011 10/03/2015 24/03/2011 289C187B.zip
2011 12/12/2011 12/12/2015 03/2012 4FD9C341.zip
2012 20/11/2012 20/11/2016 28/12/2012 863EA7F7.zip
2013 12/11/2013 12/11/2017 20/12/2013 12DB0C1D.zip
2014 05/11/2014 05/11/2018 16/12/2014 6C66D133.zip
2015 22/10/2015 22/10/2019 4/11/2015 DB4FD4B9.zip
2016 13/10/2016 13/10/2020 11/16/2016 9FB7502F.zip
2017 09/15/2017 09/15/2021 09/11/2017 TSA_2017.zip
2018 27/07/2018 07/27/2022 03/10/2018 TSA_2018.zip
2019 07/16/2019 07/16/2023 25/07/2019 TSA_2019.zip
2020 07/01/2020 07/01/2024 09/22/2020 TSA_2020.zip
2021 06/21/2021 06/21/2025 21/07/2021 TSA_2021.zip
2022 06/16/2022 06/15/2026 01/08/2022 TSA_2022.zip
2023 06/06/2023 06/05/2027 07/12/2023TSA_2023.zip
2024 05/21/2024 20/05/2028 06/12/2024 TSA_2024.zip