My question is, if you run your own company and there are no employees and you still qualify under assessment D what do you do in a case like this where it is requiring 2 or more people? On a related question, at some point at least 1 person programming code would be able to get or see all of the key even if it was split between different people because the code would require the full key to decrypt data, if they have access to the code they have access to the key so how is that supposed to be handled?

3.6.6 Do cryptographic key procedures include split knowledge and dual control of cryptographic keys (for example, requiring two or three people, each knowing only their own key component, to reconstruct the whole key), for manual clear-text key-management operations? Note: Examples of manual key management operations include, but are not limited to: key generation, transmission, loading, storage and destruction.

1 Answer 1


At some point you will have to trust some code, somewhere. This is why audit procedures involve source code review and background checks on developers.

For the practical way to split and reassemble a secret, a reasonably strong way is to make the reassembly only on a "safe" machine, under visual scrutiny of the secret part holders. A "safe" machine can be a laptop which:

  1. Is kept in a safe or a reasonably sturdy locked cupboard when not in used.
  2. Is booted off a CD-ROM or a write-protected USB key when it should be used.

This kind of thing can be arbitrarily expanded upon, depending on the amount of safety or paranoia you have to contend with (e.g. put the machine in a bunker with armed guards; hire external auditors whenever you come close to the machine; use Hardware Security Modules to run the code which uses the rebuilt secret...).

  • What about the situation where there is only one person in the company (programmer/owner). Do you not fail 3.6.6 validation because you can't split the key since there is no one else involved in the company?
    – Danny
    Commented Apr 26, 2013 at 2:51

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