TOOLS / MAC

MAC ISO 9797-1

Calculate Algorithm 1 and Algorithm 3 MAC.

Algorithm

Single DES CBC-MAC · 8-byte key · zero IV.

Padding method

Zero-pad to an 8-byte boundary; aligned data gets no extra block. Empty data uses one zero block.

Calculator reference

Verification evidence and limitations →

What it calculates

Computes a DES CBC-MAC or a retail MAC.

Inputs and methods

Algorithm 1 uses an 8-byte DES key; Algorithm 3 uses a 16-byte TDES key. HEX input and mode-specific padding.

Worked example

Select Algorithm 3, Method 1, key 0123456789ABCDEFFEDCBA9876543210, data HEX 4E6F77206973207468652074696D6520666F7220616C6C20.

A1C72E74EA3FA9B6

Specification and limits

The example is ASCII “Now is the time for all ” including its final space. Input padding changes the result.

ISO 9797-1 catalogue ↗