>The only problem I have is that the part regarding current encryption are a little outdated. But the rest of the content is good, I've found.

How do you figure? The book ends with public key cryptography, PGP, and quantum code. Those seem about as relevant as they were in 99.

A modern introduction would explain AEAD, elliptic curve algorithms and the need for/ implementation of PFS.

In terms of specifics like PGP it would today make more sense to describe Signal which you can relate to an ordinary user by telling them that's how WhatsApp works.

The issue is not with encryption, the subjects are still relevant. What I meant is that the state of the art has changed, the situation has evolved and I would have liked to read the author's opinion on it.

>There's also a part on how the secret on Enigma's breaking has been kept for decades after the war, supposedly because Enigma machines had been distributed to British colonies (and ex-colonies) and British intelligence wanted to be able to decrypt their communication.

Not to mention any units captured by the Soviets - GCHQ wanted to make sure any use of the units by them would be decryptable as well.

GCHQ and it’s American counterparts were more interested in deceiving the Soviets into believing that they hadn’t been able to break a type of cipher unrelated to Enigma, namely the pseudo-Vernam Ciphers as embodied by Tunny/Lorenz/* Geheimschreiber* for transmitting stream-enciphered teleprinter traffic (as decoded by Colossus). Enigma was trivial by comparison and it’s insecurity was known to the USSR.