# Article 35 — Security of communication session **Commission Delegated Regulation (EU) 2018/389 · binding · OJ L 69, 13.3.2018 · dated 27 Nov 2017 [in force]** *In force · Consolidated version of 12 September 2023 · Checked against EUR-Lex on 26 Oct 2026 · [Official source](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02018R0389-20230912)* 1. Account servicing payment service providers, payment service providers issuing card-based payment instruments, account information service providers and payment initiation service providers shall ensure that, when exchanging data by means of the internet, secure encryption is applied between the communicating parties throughout the respective communication session in order to safeguard the confidentiality and the integrity of the data, using strong and widely recognised encryption techniques. 2. Payment service providers issuing card-based payment instruments, account information service providers and payment initiation service providers shall keep the access sessions offered by account servicing payment service providers as short as possible and they shall actively terminate any such session as soon as the requested action has been completed. 3. When maintaining parallel network sessions with the account servicing payment service provider, account information service providers and payment initiation service providers shall ensure that those sessions are securely linked to relevant sessions established with the payment service user(s) in order to prevent the possibility that any message or information communicated between them could be misrouted. 4. Account information service providers, payment initiation service providers and payment service providers issuing card-based payment instruments with the account servicing payment service provider shall contain unambiguous references to each of the following items: **(a)** the payment service user or users and the corresponding communication session in order to distinguish several requests from the same payment service user or users; **(b)** for payment initiation services, the uniquely identified payment transaction initiated; **(c)** for confirmation on the availability of funds, the uniquely identified request related to the amount necessary for the execution of the card-based payment transaction. 5. Account servicing payment service providers, account information service providers, payment initiation service providers and payment service providers issuing card-based payment instruments shall ensure that where they communicate personalised security credentials and authentication codes, these are not readable, directly or indirectly, by any staff at any time. In case of loss of confidentiality of personalised security credentials under their sphere of competence, those providers shall inform without undue delay the payment services user associated with them and the issuer of the personalised security credentials.