End To End Encryption

End to end encryption provides an enhanced layer of security for swiped and keyed transactions by encrypting the card data at point of entry. For swiped transactions this typically happens in the mag reader head, for keyed transactions, this happens in a standalone, tamper resistant keypad. The data remains encrypted while it passes through the device, software and communication channels to the gateway. Once in the secure environment of the gateway it is decrypted and used for processing.

Encrypted card data may be passed in the same fields as the clear text card and swipe data is passed. The data must be proceeded by “enc: / /” and base 64 encoded. For example, if the following data is read from the device:

%B4444*********7779^EXAMPLE TEST CARD^2512*********?;4444*******7779=2512*********?|0600|411785952BA27844F49434FFC261A5CE6E6F3F46BE836D8612B56A53DB480167FD63DA9892B0F471626CDC0B75376AF6759403CA58A4C263|350518BC1F8D63CBD2C47D19FC3C1824D3AFB5CC54AC878595902B927DE850D3||61400200|19CFF0CF6F24A9FAFAFF80EF8258F1C1A81A9D90DB474413E127206B3C32DF4885223C20777CB9FAB21D38864B92BDA43D6699610EDC7D62|C516F135E93DFEB|25776C75DC32EEFD|FFFF87BABCDEF000001|1316||0000xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

You would submit the following in the UMmagstripe variable or CreditCard.MagStripe:


Data Format

The encrypted card data can be passed in several different formats. If using a supported manufacturer, it is required that the developer pass the entire block of data as it was read from the reader. It is important that the gateway receive all data components to be able to decrypt successfully. The most common mistake made by developers is to send only the encrypted data and omit the KSN block which contains the key info necessary for decryption. The following formats are supported:

IDTech Format

Devices that use IDTech heads will output DUKPT encrypted data. The data block should start with \x02 followed by two bytes indicating length, followed by \x80 or \x85. Some devices may output raw binary while others may return a binhex encoding.

Magtek Format

Supported Magtek devices output a pipe “|” delimited format. The entire block of data is needed for decryption. See below for an example.

Generic Format

For developers implementing their own encryption or using an unsupported device, the data can be sent in json format with the fields below. When using this format it is not necessary to base64 encode the entire block, just the encrypted data element.

Field Required Description
k yes Key ID. For DUKPT based encryption this should be the full KSN block in binhex format including the KSID, device serial and encryption counter
t yes* All tracks encrypted in one data block. This should be either base64 or binhex encoded.
t1 yes* Encrypted track 1 data. This should be either base64 or binhex encoded.
t2 yes* Encrypted track 2 data. This should be either base64 or binhex encoded.
t3 yes* Encrypted track 3 data. This should be either base64 or binhex encoded.
m no Masked track data, all tracks in single string
c no Encrypted, manually keyed card number and expiration.

* Device will either concatenate all tracks together before encryption or encrypt each track individually. Use t if encrypted all together in single block and use t1, t2, t3 if encrypted separately.

enc://{"k":"FFFF9019F8E999000009","t1":"411785952BA27844F49434FFC261A5CE6E6F3F46BE836D8612B56A53DB480167FD63DA9892B0F471626CDC0B75376AF6759403CA58A4C263","t2":"350518BC1F8D63CBD2C47D19FC3C1824D3AFB5CC54AC878595902B927DE850D3","m":"%B4444*********7779^EXAMPLE TEST CARD^2512*********?;4444*******7779=2512*********?"}

iDynamo Library

If you are using idynamo library, here is what you need to do:

NSString *responseString = [mtSCRALib getResponseData];
NSData *responseData = [responseString dataUsingEncoding:NSASCIIStringEncoding];
NSString *encodedString = [NSString stringWithFormat:@"enc://%@", [^] [responseData base64Encoding]];

and then send encodedString to the gateway as MagStripe.

developer/endtoendencryption.txt · Last modified: 2015/01/19 16:32 by tem

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