SB nº 252: Chaining Invocation & Block Size

EMV^® Specification Bulletin No. 252 First Edition December 2020 Chaining Invocation & Block Size This Specification Bulletin updates the requirements related to chaining.

Applicability

This Specification Bulletin applies to:

• EMV Level 1 Specifications for Payment Systems, EMV Contactless Interface Specification, Version 3.0 – February 2018.

Related Documents

• None

Description

This Specification Bulletin implements the following updates:

• It introduces a new requirement that defines when a PCD must invoke chaining
• It introduces a new requirement that defines when a PICC must invoke chaining
• It changes the requirement for the size of the PCD’s chained blocks. The size of the PCD’s chained blocks becomes the minimum of the FSC indicated by the PICC, and the maximum FSC supported by the PCD. countries. Specification Changes Add new Requirements 10.3.2.1a and 10.3.2.1b to new Requirements 10.8. Requirements 10.8: Chaining Invocation PCD PICC 10.3.2.1a The PCD shall invoke chaining when the number of data bytes in the frame to be sent exceeds the minimum of:
• FSC indicated by the PICC, and
• Maximum FSC supported by the PCD which shall be at least 256 bytes. Refer to Table 5.17 (for Type A) and Table 6.7 (for Type B) for possible values of FSC greater than 256 bytes. 10.3.2.1b The PICC shall invoke chaining when the number of data bytes in the frame to be sent exceeds the minimum of:
• FSD indicated by the PCD, and
• Maximum FSD supported by the PICC. Refer to Table 5.14 (for Type A) and Table 6.15 (for Type B) for all possible FSD values. Change requirement 10.3.2.2 as follows: PCD 10.3.2.2 When the PCD sends a chain of I-blocks, each block indicating chaining (i.e. all blocks of the chain except the last one) shall have a length equal to the minimum of:
• FSC indicated by the PICC, and
• Maximum FSC supported by the PCD which shall be at least 256 bytes. Refer to Table 5.17 (for Type A) and Table 6.7 (for Type B) for possible values of FSC greater than 256 bytes. PCD chaining buffer size. The PCD chaining buffer size is equal to FSC if supported by the PCD or FSCCHAINING if FSC is greater than FSCCHAINING and FSC is not supported by the PCD. Refer to Annex A.4 for the value of FSCCHAINING. countries. Change title of Requirements 10.7 to "General Chaining Rule" and update numbering of requirements tables in Chapter 10 following the introduction of Requirements 10.8. Remove FSCCHAINING from Table A.5. Topic Parameter Common … FSCCHAINING … Table A.5: Sequences and Frames PCD Value PICC Value Units Min Max Min Max 256 bytes countries.

Legal Notice

The EMV^® Specifications are provided "AS IS" without warranties of any kind, and EMVCo neither assumes nor accepts any liability for any errors or omissions contained in these Specifications. EMVCO DISCLAIMS ALL REPRESENTATIONS AND WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT, AS TO THESE SPECIFICATIONS. EMVCo makes no representations or warranties with respect to intellectual property rights of any third parties in or in relation to the Specifications. EMVCo undertakes no responsibility to determine whether any implementation of the EMV^® Specifications may violate, infringe, or otherwise exercise the patent, copyright, trademark, trade secret, know-how, or other intellectual property rights of third parties, and thus any person who implements any part of the EMV^® Specifications should consult an intellectual property attorney before any such implementation. Without limiting the foregoing, the Specifications may provide for the use of public key encryption and other technology, which may be the subject matter of patents in several countries. Any party seeking to implement these Specifications is solely responsible for determining whether its activities require a license to any such technology, including for patents on public key encryption technology. EMVCo shall not be liable under any theory for any party’s infringement of any intellectual property rights in connection with the EMV^® Specifications

countries.