Continue on PC

4 09 2018

The majority of computer users is into Microsoft’s Windows as their preferred desktop operating system because of many good reasons.

But when it comes to smartphones Microsoft tried it but failed miserably. Devices running Android and iOS dominate with a market share of 99%. If you don’t have a significant share in the mobile market just support the behemoths Android and iOS. So Microsoft now focuses on software to bring their services to Android and iOS users. And it works.

An interesting and quite useful service is “Continue on PC”. It allows to start actions on an Android or iOS device and continue it on a PC running Windows 10.

Look at my image.

It shows an iPhone with an installed version of Microsoft’s browser Edge. I opened Apple’s homepage, tapped on the smartphone control top left and chose Surface Pro4 as the device to continue browsing on. The website immediately opens on my Surface.

This feature works perfectly with my Surface, an iPhone 6s Plus running iOS 11, a Microsoft Lumia 550 running Windows 10 Creator’s Update and a Nokia 6.1 running Android 8.1 Oreo.

More about how to connect devices …

Connect phones to Windows 10 PCs

Other Microsoft products for iOS

• Office
• Outlook
• One Drive
• Office Lens
• Authenticator
• Remote Desktop

I use them all and they are really great.

Thanks for reading
and thanks to Aditya Tivari.

Apple, your signature please

28 08 2018

Every once in a while we can read news like this:

“Apple has stopped signing iOS X.y.
iPhone, iPad, and iPod touch owners who have upgraded to the latest version will no longer be able to downgrade to earlier versions of iOS.”

iOS versions – like all other software coming from reliable sources – are distributed over the Internet only because media like the old fashioned Floppy Disk with IBM DOS on it are a bit outdated. Today’s Internet users need assurance that they can trust web sites and downloads because of the potential damage or piracy that software can cause.

A Code Signing Certificate allows IT developers like Apple to digitally sign their software before it’s distributed over the Internet. With it they add a layer of assurance that tells users that their software can be trusted, isn’t modified since it was signed and does not come from a malicious source.

Apple routinely stops signing older versions of software updates after new releases come out in order to encourage customers to keep their operating systems up to date.

How does “Signing iOS X.z” work?

A small piece of software adds a certificate issued by a Certificate Authority (CA, here it’s Apple) to the Software to be signed. It generates a one-way hash value (see below) of the software and uses the private key issued to the developer from the CA to encrypt this hash and bundles the hash and certificate with the software. From now on the software and the certificate are an entity.

When a user receives the software, he (isn’t able to do it but a feature in his operating system) verifies it by decrypting the hash using the public key in the certificate, creates a new hash of the downloaded application and compares the new hash with the hash that was signed with the certificate. If the two hashes match, the user knows that the application has not been modified since it was signed and its source is the developer who once applied for his personal certificate.


A HASH function is any function that can be used to map data of arbitrary size to data of a fixed size. A cryptographic hash function allows to easily verify that some input data – an iOS version or the modified parts – maps to a given hash value. A very, very simple and not very secure hash function would be to count the number of words in my post. The app I use to write posts tells me: 410 words. If you contact me and it’s not the number I tell you, the post was modified by someone else.

Thanks for signing reading.


24 08 2018


Well, here are the results of a survey in the USA with 2,500 customers and their reasons why they switched from the leading to the competing platform and and vice versa.

Switching Android <-> iOS