Learn Arabic (Modern Standard): التوثيق من أبطأ الإجراءات. - Authentication is one of the slowest procedures.

In Arabic, the structure من (from) followed by an adjective in the superlative pattern (أفعل) and a definite plural noun is the standard way to say "one of the [most/least]...". You are literally saying it is "from the slowest of procedures."

What verb form does the word التوثيق (authentication) come from?

It is the verbal noun (masdar) of the Form II verb وثّق (to document, authenticate, or certify). The pattern تفعيل (taf'eel) is the standard verbal noun for Form II verbs, which often indicate making something happen or formalizing an action.

The adjective for "slow" is بطيء (batee'). How does it become أبطأ (abta') here?

To make a superlative like "slowest", Arabic takes the root letters ب-ط-ء and puts them into the أفعل (af'al) pattern. Because the letter before the final hamza now has a fatha (short 'a' sound) instead of a kasra, the spelling rules dictate that the hamza sits on an alif (أبطأ) instead of a yaa.

The singular word إجراء (procedure) is masculine. Why does it take the feminine plural ending in الإجراءات?

Many non-human verbal nouns (masdars) from derived verb forms, like this Form IV noun, take the regular feminine plural ending ـات regardless of their singular gender. This is a very common pattern in Modern Standard Arabic for official, organizational, or technical terms.