It follows the recent spate of terrorist attacks, not least of all the suicide bombing which killed 22 people and injured more than 100 others at American singer Ariana Grande’s Manchester Arena.
But while bag searches may take a little longer festival-goers should get on site faster after an investment in extra training, resources and bigger entry lanes, he said.
The biggest change will be allowing only A4-sized bags into the main arena itself - which is now common practice at most concert venues.
Backstage security will also be tighter than ever with sniffer dogs used on production vehicles at the venue in Bramham Park.
The measures apply to his Leeds and Reading double header festivals - both on August 25 to 27 - where this year's big names include Eminem, Kasabian, Muse and ex-Oasis frontman Liam Gallagher.
VIDEO: Watch Melvin Benn's interview with Graham Walker on our YouTube player.
TICKETS: For tickets, updates, safety information and more visit www.leedsfestival.com and www.readingfestival.comMelvin, managing director of Festival Republic, produced the One Love Manchester benefit concert which raised over £10m in response to the attack - bringing together artists including Coldplay, Miley Cyrus, Justin Bieber, Katy Perryand Take That.
He said they have learned an enormous amount about improving security at that and other recent concerts.
There has also been a swift culture change in concert-goers embracing new measures, including reducing what they take into events to speed up entry queues, he said.
"At Leeds and Reading, like all other festivals this year, we are providing an environment that is as safe as is possible.
"Trust me, we are working with terrorism experts in West Yorkshire Police, Thames Valley Police and up and down the country.
"Our security provision has gone up vary dramatically and when I say dramatically, I mean dramatically.
"We are investing in a huge amount of extra training and resources, in order to provide that reassurance.
"In the main there won't be that much more additional delay. The bag searches on the campsite entrances will be what the bag searches have always been. There will be increased security, but we will put extra resource in to make the lanes bigger and people will be able to come through faster."
He dded: "In fairness, security at the festivals has generally been good anyway and people know what they should and shouldn't bring.
"The big change really will be particularly in terms of the arena - we will only be allowing in bags the size of an A4 sheet of paper. That will allow people to bring a rain mac or a bottle of water, or a sandwich, or whatever it is that they normally bring into the arena.
"There will be sniffer dogs used on production vehicles coming in.
"We just went through it at Download Festival. It was incredibly successful. We also learned an enormous amount putting on the One Love Manchester concert.
"What we are doing, very rapidly, is beginning to change the culture and people are embracing it - that's the amazing thing. People know now that actually they get speedy access by not bringing lots of things in.
"I was at Dublin at an Arcade Fire gig and everybody walked in with their phone in one hand, their wallet in the other and their jackets open. They got speedy entry because you can do a really quick search and that's what we are really moving into.
"This isn't just about the concerts, it's about every aspect of life. We are in a changed world. But we're not giving in to any of these threats or demands or anything like that, we are just working through it.
"Our lines will continue in exactly the same way that they did, but we will be a little bit more careful in the entering and leaving of some of the spaces
* Melvin, who describes his festival role as the 'little bit in the middle, bringing fans and bands together', also revealed the act he is most looking forward to seeing most on the bill this year.
"It's impossible for me not to say Eminem because he genuinely changed music and his words are incredibly important to not just my generation, but all generations before me," he said.
"Every band has got their place in the world, in terms of what they are saying to young people. Eminem will be huge for me, as will Giggs and Kasabian - they are part of the family. Kasabian stayed out in our mosh pit and are now headliners. if you've got a British band that loves playing live, that loves football and love having a beer, I mean crikey, you can't go wrong can you?
"There's a strong rock tradition - clearly this year Kasabianand Muse very much fit into that. Eminem brings in the hip hop element, but what we have done over the years is really open the festival up so there's also a strong dance, hip hop and grime element, really really reflecting what the tastes of young people are.\
"It isn't me that makes it better every year. It's the bands that make it better because music doesn't stand still and that's the amazing thing. Live music doesn't stand still, it gets better every single year; bands get better and that's what I love about it.
"The festivals are an August bank holiday tradition - a little bit of sun, occasional rain, a huge amount of bands and an amazing weekend with your mates - really that's what it's about and yes there's still time to get tickets "