This is the Secret behind the Curse marks that boruto have in boruto : naruto next generations

According to the ongoing manga series and by some statements made by Kishimoto!

The curse marks that Boruto have are the result of orochimaru ! 

This is stated that the New curse marks are that have appeared in the latest spoilers got the people thinking about what plot is of the new upcoming manga after naruto shippuuden , Boruto : Naruto next generations !

in some places it is found out and figured out that The curse mark was the resukt of orochimaru and these enchantments were asked by sasuke uchiha himself ! sasuke uchiha is the sensei of The son of naruto ! Boruto . 

Orochimaru 

Orochimaru was always upto something that was strong ! in-spite his hunger towards ninjutsu and kekkei-genkai's he developed many jutsu's of his own and also one of them was curse mark . because of curse mark ! orochimaru was able not only to distribute his power , but it also helped him to revive if his body had already been destroyed ! that was a perk of revival from his curse mark !

it is being told that sasuke uchiha asked orochimaru to develop a curse mark for boruto that could help him with chakra control and other things ! this curse mark is totally different from what was of orochimaru ! and it also gave him a boost of instant chakra . naruto had the nine tails chakra but boruto didnt had any of the special traits ! so it was asked by sasuke uchiha to make a curse mark for boruto !

Sasuke Uchiha (adult)
 

Later on orochimaru passed the curse mark to his own son ; mitsuki , he was a test subject that came out as same powers and appearance same as orochimaru ! till now only 3 person are  confirmed with the curse marks in boruto series ! and they are Boruto , Mitsuki and Kawaki

Boruto & Mitsuki (curse mark)