Do not look behind the curtain
While national intelligence agencies are making a lot of noise about encryption, causing outrage and incredulity that they can be so stupid about the 'laws of mathematics', they are busy making use of all the already existing 'back doors', and using this as a pretty successful distraction strategy.
As several commentators have pointed out in this and previous articles on this topic, One Time Pads and dictionaries of code-phrases* are uncrackable in themselves without a copy of the One Time Pad or the code-dictionary.
However, as students of secure communication learn at their mothers knee, it is very important to ensure that your security end-point is separate to your communications end-point. It doesn't matter how well your message is encrypted if you decode it on a completely compromised piece of equipment so the plain text lovingly decoded can be grabbed and exfiltrated. The average member of Joe Public cannot obtain uncompromised hardware. The military find it difficult.
The 'secure' phones compromised by the Dutch police had malware inserted on the phones that took copies of the decoded messages. All of the apps on mobile phones rely on the operating system, the processor, and the modem, none of which the user has control over**.
In addition, theoretically good encryption is compromised by poor implementations that have gaping side channels. The AES code produced to show how AES worked, and used as a basis by many people had not been hardened against timing attacks etc. So a good algorithm generated by an open evaluation process was compromised in many applications because the side channels were easily exploitable. Having a good algorithm is less than half the battle: making sure the implementation in hardware is secure is hard.
So while the security services are making a song and dance about encryption, they are busily exploiting all the flawed implementations, 'influencing' standards committees to adopt standards that are difficult to implement well, and making sure, probably with the help of Hollywood and the MPAA that any equipment you can buy implements 'Trusted Computing', which is to say, trusted by them to execute programs you have no control over.
If you want to send a secure message, encrypt it on hardware you can trust: which might be pencil and paper, and only put the encrypted text on the communications link. Even then, unless you have thought in advance how to deal with the metadata, you won't be as safe from discovery as you think.
It's all a game of misdirection. If you want to send secret messages easily, campaign for open hardware that can be audited down to gate-level, designed by people who understand about side-channels. Even then, unless you have a good plan on how to deal with the metadata trail, you won't be able to hide from 'the authorities' for long if they really want to find you.
*e.g. 'the swan flies south for the winter' means 'cancel the operation to put polonium in the targets tea'
**There are a few nerdy exceptions for the operating system, and possibly the bootloader. Not exactly mainstream, though.