high security keys (ASP)

Is there a high security key that is compatible with the ASP cuff? Yuil keys appear to be very similar, are they?

There is no such thing as a high security key for an asp handcuff. The ASP handcuff utilizes a standard handcuff key. Most Yuil handcuffs also use a "standard" handcuff key. However they offer a more secure handcuff that requires a spaced bitted key because of how the pawls are placed in their particular higher security handcuff body.

And as for "standard" handcuff keys?? You'll find that there are variations in thickness of the keys or the key bit posts as well as the various cuff body thickness found on the various manufacturers which sometimes don't allow you to open one brand of cuffs or another using a "standard" handcuff key from one manufacturer to another due to different manufacturing anomalies of the various brands of handcuffs!

A high security key is for a handcuff that is designed as high security? Although it may be designed as such many are genuinely not all that high security!

In particular the ASP Brand Handcuffs in my humble OPINION are Not High Security but rather are a dangerous gimmick that has been eaten up by the easily awed Police and Correctional people who have been swayed based upon a Great Marketing campaign that actually risks there lives as well as the publics that these security people have sworn to protect !!

Is there a high security key that is compatible with the ASP cuff? Yuil keys appear to be very similar, are they?

Yuil keys are a larger diameter from the ASP and aren't compatible. ASP high security locks are warded so a standard key will not work. However, keys can be made by simply cutting the ward slot in a standard key with the appropriate thickness jewler's saw or file.