Discontinuation of Existing Encrypted Message Mechanism · NSE/MSD/76883
NSE circular NSE/MSD/76883 · 13 Oct 2026
Official title
Discontinuation of Existing Encrypted Mechanism of interactive Messages in CM, FO, CD and COM Segments
Official record
Open source pageSummary
Check the official recordWhat changed
The National Stock Exchange of India discontinues the existing encrypted message mechanism for CM, FO, CD, and COM segments on December 07, 2026. Members must migrate to the new encryption mechanism with MD5 checksum removal or the new encryption mechanism with immediate acknowledgement of order messages before this date. The exchange terminates support for existing ports on the specified date and grants no extensions. Members using NNF, NEAT, or NEAT Adapter must update their gateway router configurations to the new parameters provided by the exchange.
What you must do
- Migrate to the new encryption mechanism with MD5 checksum removal or the new encryption mechanism with immediate acknowledgement of order messages.
- Update gateway router configurations to the new ports and parameters for NNF, NEAT, or NEAT Adapter.
Key dates
Document text
National Stock Exchange of India Limited
Circular
Department: MEMBER SERVICE DEPARTMENT
| Download Ref No: NSE/MSD/76883 | Date: October 13, 2026 |
|---|---|
| Circular Ref. No: 67/2026 |
All Members,
Discontinuation of Existing Encrypted Mechanism of Interactive Messages in CM, FO, CD and COM Segments
This is in reference to circulars NSE/CD/70422 dated September 25, 2025, NSE/COM/71599 dated December 02, 2025, NSE/CMTR/72769, NSE/FAOP/72763 dated February 12, 2026, and NSE/MSD/75014 dated July 02, 2026 regarding introduction of ‘new encryption mechanism with MD5 checksum removal’ and ‘new encryption mechanism & immediate acknowledgement of order related messages’.
As outlined in the circular, an interim coexistence period is currently in effect, during which encrypted message traffic using both the new and existing encryption mechanisms are being accepted.
Members are hereby informed that the existing encryption mechanism will be discontinued with effect from December 07, 2026.
The important instructions for implementation are provided below:
- Members are requested to note the coexistence timelines below, as the existing encryption mechanism through the old port will be discontinued:
| Segment | Gateway Router | Date of Discontinuation | |
|---|---|---|---|
| IP Address | Existing Port | ||
| CM | 172.19.12.85 | 10827 | December 07, 2026 |
| FO | 172.19.13.85 | 10837 | |
| CD | 172.19.18.85 | 10885 | |
| COM | 172.19.15.85 | 10865 | |
- Members using NNF are advised to take note of below parameters and plan to mandatorily migrate to either ‘new encryption mechanism with MD5 checksum removal’ or ‘new encryption mechanism & immediate acknowledgement of order related messages’ :
| Segment | Gateway Router | Gateway IPs Subnet ranges | |||
|---|---|---|---|---|---|
| IP Address | New Port | Network | Mask | Port | |
| CM | 172.19.12.85 | 10831* | 172.19.12.0 | 255.255.255.128 | 10810 |
| 10833** | |||||
| FO | 172.19.13.85 | 10841* | 172.19.13.0 | 255.255.255.128 | 10820 |
| 10843** | |||||
| CD | 172.19.18.85 | 10889* | 172.19.18.0 | 255.255.255.128 | 10870 & 10871 |
| 10891** | |||||
| COM | 172.19.15.85 | 10869* | 172.19.15.0 | 255.255.255.128 | 10850 |
| 10871** | |||||
*Port – This port will support new encryption messages with MD5 checksum removal.
**Port - This port will support new encryption messages with MD5 checksum removal and new immediate Ack request for order related messages.
- Members using NEAT / NEAT Adapter shall have use the below interactive parameters :
| Segment | Gateway Router | Gateway IPs Subnet ranges | |||
|---|---|---|---|---|---|
| IP Address | New Port | Network | Mask | Port | |
| CM | 172.19.12.85 | 10831 | 172.19.12.0 | 255.255.255.128 | 10810 |
| FO | 172.19.13.85 | 10841 | 172.19.13.0 | 255.255.255.128 | 10820 |
| CD | 172.19.18.85 | 10889 | 172.19.18.0 | 255.255.255.128 | 10870 & 10871 |
| COM | 172.19.15.85 | 10869 | 172.19.15.0 | 255.255.255.128 | 10850 |
Accordingly, members are advised to plan and complete their migration activity on or before the stipulated deadline. Members are further requested to note that no extension will be granted beyond the discontinuation date of the existing facility.
Please note all other details as mentioned in the aforementioned circulars shall remain unchanged.
For and on behalf of
National Stock Exchange of India Limited
Khushal Shah
Associate Vice President
| Toll Free No | Email id |
|---|---|
| 1800-266-0050 (Option 1) | msm@nse.co.in |
Source details
- Source
- National Stock Exchange of India
- Type
- circular
- Published by source
- 13 Oct 2026
- Document number
- NSE/MSD/76883
- Issuing division
- MEMBER SERVICE DEPARTMENT
- Effective date
- 07 Dec 2026
- Coverage area
- securities