In Chapter 1 of Singh’s The Code Book, he states that “The cipher of Mary Queen of Scots clearly demonstrates that a weak cipher can be worse than no cipher at all”. Singh means that sometimes having a layer of security can be more detrimental than having none at all because it gives the sender and receiver a false sense of security.
If the sender and receiver are under a false sense of security due to their encryption, they are under the assumption that if it is intercepted it will not be deciphered. Thus, they may be think it is fine to make their intentions clear in the passage, or even worse, give details of other unnecessary information. However, this provides incriminating evidence in ‘black and white’ — literally. This is demonstrated by Babington’s ease in providing details of the plot to Queen Elizabeth as well as providing the names of his co-conspirators. However, if there was no encryption, both sender and receiver would be more inclined to make sure the message didn’t contain any information that could incriminate them as well as taking further measures to ensure that the message doesn’t get into the hands of the enemy, unlike Babington’s trust of Gifford, who was acting as a double agent. Singh also implies that people who, like Babington, tried to keep their messages safe through ciphers often overestimated the strength of their ciphers. This often lead to an incorrect feeling security which in turn ended badly, and in some cases tragically.
To conclude, looking back at the tragic story of Queen Mary, Singh suggests that even though you may encipher your text, you should not feel overly comfortable or safe. Rather, you should err on the side of caution, both in the delivery and in the content of the message that has been encrypted.