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certificate authorities  

(CAs)

, and various bodies such as banks and the Post Office are likely to fulfil this role. 

That message is called a certificate. In reality, as asymmetric encryption is rather slow, it is 

often only a sample of the message that is encrypted and used as the representative digital 

signature.

Example certificate information could include:

● 

user identification data;

● 

issuing authority identification and digital signature;

● 

user’s public key;

● 

expiry date of this certificate;

● 

class of certificate;

● 

digital identification code of this certificate.

It is proposed that different classes of certificates would exist according to the type of infor-

mation contained. For example:

● 

name, email address

● 

driver’s licence, national insurance number, date of birth

● 

credit check

● 

 organisation-  specific  security  clearance  data.