我必须处理瑞士邮局在 USB 令牌上颁发的证书。在同一个令牌上交付两个证书。在其预期使用领域中，一个具有“不可否认性”，另一个具有“数字签名”。
现在，我无法理解两者之间的实际区别是什么：我总是在同一个证书中看到两个证书，而从来没有看到两个证书具有相同的身份，每个证书都具有一个角色。事实上，我无法想象不可否认性和数字签名不同的场景，对于所有实际问题来说，都是同一件事。
有人可以向我解释一下有什么区别吗？如果您对在什么情况下应该选择其中一个而不是另一个提出建议，那也会有所帮助。
I have to deal with certificates issued by the Swiss post office on USB tokens. There deliver two certificates on the same token. In their intended usage fields, one has "non repudiation" and the other "digital signature".
Now, I can't understand what the practical difference between the two are: I've always seen both in the same certificate, never two certs for the same identity each with one of the roles. In fact, I can't imagine a scenario where non-repudiation and digital signature aren't the same, for all practical matter, the same thing.
Could anyone explain to me what the difference is, please ? And if you had a suggestion about in what situation one should be picked over the other, that would help as well.s
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我意识到这个问题有点老了，但我想我可以对这个问题提供一些急需的启示。
keyUsage 属性中的不可否认性值与整个证书相关，而不是与任何特定目的相关。不可否认标志的存在表明私钥具有足够的保护，证书中指定的实体以后无法否认（拒绝）他们对证书采取的操作。该标志的存在并不能阻止否认，而是表明否认不可能通过合理的审查。
因此，在这种特定情况下，CA 为用户提供包含或不包含不可否认元素的证书选项。如果您想向那些验证签名的人断言您无法轻易否认签名是您本人（USB 令牌是此处的密钥启用程序），请使用不可否认证书。否则，请使用标记为数字签名的证书。 （根据证书中的其他属性，您可能无法使用其中一个或两个证书签署文档。）
请参阅 Wikipedia：http://en.wikipedia.org/wiki/Non-repudiation
另请参阅相关 RFC：http://www.faqs.org/rfcs/rfc3280.html（第 4.2.1.3 节）
I realise this question is a bit old, but I think I can shed some much-needed light on the question.
The non-repudiation value in the keyUsage attribute relates to the whole certificate, not any purpose in particular. The presence of the non-repudiation flag indicates that the private key has sufficient protections in place that the entity named in the certificate cannot later repudiate—deny—actions they take with the certificate. The presence of the flag doesn't prevent repudiation, rather it indicates that repudiation isn't likely to survive reasonable scrutiny.
So in this specific case, the CA is giving the user the option of a certificate that does or does not include the non-repudiation element. If you want to assert to those verifying the signature that you can't easily deny it was you who signed it (the USB token is the key enabler here), use the non-repudiation certificate. Otherwise, use the certificate marked for digital signatures. (Depending on the other attributes in the certificate, you may or may not be able to sign documents with either or both certificates.)
See Wikipedia: http://en.wikipedia.org/wiki/Non-repudiation
See also the relevant RFC: http://www.faqs.org/rfcs/rfc3280.html (section 4.2.1.3)
我与实现它的人交谈过，显然，他们打算使用“不可否认”证书来/真正/签署文档，并将“数字签名”证书用于身份验证。
I talked to the guy who implemented it and, apparently, they intended the "non-repudiation" cert for /really/ signing documents and the "digital signature" one to be used for authentication.
“数字签名”是指您可以保证文档的来源或用户的身份；这就是身份验证。
“不可否认性”意味着文件被批准，这是内容承诺也称为电子签名（不是数字签名）。
希望这对您有所帮助，因为即使在 2013 年，人们也总是问这个问题。
"digital signature" means that you can guarantee the origin of the document or the id of the user; this is AUTHENTICATION.
"non repudiation" means that the document is approved, this is content commitment also called ELECTRONIC SIGNATURE (not digital signature).
Hope this helps because one's always asked this question even in 2013.
有趣的问题，你的想法与我的想法相符。
我在 IBM 这里介绍了密钥的用法，但我仍然无法真正理解其中的区别。
我读完这篇文章后所能表达的最好的理解是，不可否认的用法意味着“我真的想要签署这个，并且我真的理解签名的含义这。”
抱歉，这不是一个完整的答案，但我希望它有所帮助。
编辑 2014 年 4 月 4 日
我再次获得更多积分。 @Calrion 的答案要好得多，因此请以这种方式发送任何 +1。
Interesting question, and your thoughts match my own.
I've found a reference at IBM here about key usage, but I still can't really get my head around the distinction.
The best that I can phrase my understanding having read the article is that a non-repudiation usage means "I really meant to sign this, and I really understand the implications of signing this."
Sorry this isn't a complete answer, but I hope it helps.
EDIT 4th April 2014
I just got given more points again. The answer from @Calrion is much better, so send any +1s that way.
“数字签名”应该用于身份验证（是您签署的），而“不可否认”意味着您知道您签署了什么。
如果您使用私有证书进行身份验证（针对某些服务器），则身份验证按以下方式工作：在建立连接期间，您的浏览器（或其他软件）签署服务器提供的一些随机数据，以证明另一端是您。但关键是您无法控制要签名的数据。因此，服务器可以发送“我，Petr Novonty，把我所有的钱给 James Clark”，而不是发送随机数据。
为了避免这种情况，用于签署某些文档的密钥应该设置“不可否认”而不是“数字签名”位。
"digital signature" should be used for authentication (it was you, who signed this), while "non repudiation" means that you know what you was signed.
If you use your private certificate for authentication (against some server) the authentication works following way: During establishing the connection your browser (or other SW) signed some random data provided by server to prove that it was you on the other side. But the key point is that you have no control which data you are signing. Thus the server can you send instead of random data send "I, Petr Novonty, give all my money to James Clark."
To avoid this, key used for signing some documents should have "non repudiation" and not "digital signature" bits set.
此页面对所有关键用法进行了较为清晰的描述：
This page gives somewhat clear descriptions of all the key usages:
请记住，X.509 重命名了
contentCommitment中的nonRepudiation位。这似乎比用“非”来描述要好。所以这句话支持了Franck Leroy给出的答案。请注意，它们是简单的位，它们的名称仅指示密钥用法。 RFC 5280 中给出了这些位的一些解释。但是如何解释这两者之间的区别最终留给了证书颁发者。 RFC 5280 对此表示“数字签名和不可否认位之间的进一步区别可能会在特定的证书策略中提供。”
https://www.rfc-editor.org/rfc/rfc5280#第4.2.1.3节
Keep in mind, that X.509 renamed the
nonRepudiationbit incontentCommitment. This seems to be better than a description via "non". So this remark supports the answer given by Franck Leroy.Note that they are simple bits, their names give only indications for the key usage. Some explanations of these bits are given in RFC 5280. But how to interpret distinctions between these two is finally left to the certificate issuer. RFC 5280 says on this "Further distinctions between the digitalSignature and nonRepudiation bits may be provided in specific certificate policies."
https://www.rfc-editor.org/rfc/rfc5280#section-4.2.1.3