The National Stock Exchange of India Limited (NSE) on February 12, 2026, issued Circular Ref. No. 21/2026 (Download Ref. No. NSE/CMTR/72769) introducing enhancements in the Capital Market (CM) segment relating to encryption of interactive messages and immediate order acknowledgement. The circular refers to earlier Circular NSE/MSD/59984 dated December 28, 2023, under which a software-based solution combining TLS 1.3 protocol and AES-256 bit symmetric encryption was implemented to enhance security.
The Exchange has now proposed encryption of interactive messages using AES-256 bits GCM encryption with additional authentication and the provision of immediate acknowledgment for order-related messages. The new acknowledgment messages will be sent instantly upon receipt of an order, confirming successful receipt by the Exchange. These features were initially introduced in the Currency Derivatives and Commodity Derivatives segments and are now being extended to the CM segment.
An interim coexistence phase will be provided for both existing and new encryption mechanisms, after which the existing mechanism will be discontinued. New interactive parameters and NEAT Adapter version 1.0.27 will be released on April 11, 2026, while discontinuation timelines for older versions and mechanisms will be communicated separately. Members using NNF API protocols may continue with the existing CA certificate as per earlier instructions.
[Notification No. 21/2026]
